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Students can Download Social Science Geography Term 3 Chapter 2 Exploring Continents (Africa, Australia and Antarctica) Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Social Science Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Social Science Geography Solutions Term 3 Chapter 2 Exploring Continents (Africa, Australia and Antarctica)

Samacheer Kalvi 8th Social Science Geography Exploring Continents (Africa, Australia and Antarctica)Textual Evaluation

I. Choose the best answer:

Question 1.
The southernmost tip of Africa is …………..
(a) Cape Blanca
(b) Cape Agulhas
(c) Cape of Good Hope
(d) Cape Town
Answer:
(b) Cape Agulhas

Question 2.
The manmade canal through an isthmus betw een Egypt and Sinai Peninsula is
(a) Panama Canal
(b) Aswan Canal
(c) Suez Canal
(d) Albert Canel
Answer:
(c) Suez Canal

Question 3.
In respect of the Mediterranean climate, consider the following statements and choose the correct answer.
(1) The average rainfall is 15 cm
(2) The summers are hot and dry; winters are rainy.
(3) Winters are cool and dry; Summers are hot and wet
(4) Citrus fruits are grown
(a) 1 is correct
(b) 2 and 4 are correct
(c) 3 and 4 are correct
(d) All are correct
Answer:
(b) 2 and 4 are correct

Question 4.
The range which separates the west and east flowing rivers in Australia is
(a) Great Dividing Range
(b) Himalayan range
(c) Flinders range
(d) Mac Donnell range
Answer:
(a) Great Dividing Range

Question 5.
Kalgoorile is famous for …………….. mining.
(a) Diamond
(b) Platinum
(c) Silver
(d) Gold
Answer:
(d) Gold

II. Fill in the Blanks:

1. Atlas Mountain is located in …………….. continent.
2. …………….. is the first Indian research station in Antarctica.
3. ………….. is the highest peak of Africa.
4. A temperature grass land of Anustralia is called …………..
5. ………….. is the first indian research station in Antarctica.

Answer:

1. North – west Africa
2. Mt. Kilimanjaro
3. Eucalyptus
4. Downs
5. Dakshin Gangotri

II. Match the following:

1. Pinnacle – Equatorial forest
2. Krill – salt lake
3. Ostrich – small red fish
4. Lake Eyre – flightless bird
5. Jewel of the earth – Pointed limestone pillars

Answer:

1. Pinnacle – Pointed limestone pillars
2. Krill – small red fish
3. Ostrich – flightless bird
4. Lake Eyre – salt lake
5. Jewel of the earth – Equatorial forest

IV. Let us learn:

Question 1.
Assertion (A) : Aurora is a curtain of color lights appear in the sky.
Reason (R): They are caused by magnetic storms in the upper atmosphere.
(a) Both A and R are individually true and R is the correct explanation for A.
(b) Both A and R are individually true but R is not the correct explanation for A
(c) A is true but R is false.
(d) R is true but A is false
Answer:
(a) Both A and R is individually true and R is the correct explanation for A

Question 2.
Assertion (A) : A geological feature of Africa is the Great Rift Valley.
Reason (R): A Rift valley is a large crack in the earth’s surface formed by tectonic activity.
(a) Both A and R is individually true and R is the correct explanation for A.
(b) Both A and R are individually true but R is not the correct explanation for A
(c) A is true but R is false.
(d) R is true but, A is false
Answer:
(a) Both A and R is individually true and R is the correct explanation for A

V. Answer in brief:

Question 1.
Why Africa is called a “Mother Continent”?
Answer:
Africa is nicknamed as the ‘Mother Continent’ as it was the oldest inhabited continent on Earth.

Question 2.
What are the important rivers of Africa?
Answer:
The important rivers of Africa are R. Nile, R. Congo or Zaire, R. Niger, R. Zambezi, R. Orange and R. Limpopo.

Question 3.
Name the physical division of Australia.
Answer:
The Physical divisions of Australia are –

1. The Great Western Plateau
2. The Central Low lands
3. The Eastern High lands

Question 4.
Write about the nature of Antarctica continent.
Answer:

1. Antarctica is a unique continent. It does not have a native population.
2. There is no country in Antarctica.
3. It is the coldest continent with a permanent cover of ice.
4. It is the only continent called white continent.

Question 5.
Mention any four economic activities of Australia.
Answer:
Agriculture, forestry, fishing mining, manufacturing, trade and services are the major economic activities of Australia.

VI. Distinguish between:

Question 1.
Sahel and Sahara
Answer:
1. Sahel:

• Sahel is a semi-arid tropical Savanna region.
• It covers an area of 3.0 million sq km.
• It is largely a semi-arid belt of barren, sandy and rocky land.

2. Sahara:

• The world-famous Sahara desert is located in the northern part of Africa.
• It has an area of .9.2 million sq kms.
• It consists of many topographical features such as Mountain, plateaus, ergs, oases, sand and gravel covered plains, salt flats, basins and depressions.

Question 2.
Western Antarctica and Eastern Antarctica.
Answer:
1. Western Antarctica:

• The West Antarctica faces the Pacific Ocean.
• The Antarctic Peninsula which points towards the South America shows that it is the continuation of the Andes mountain range.

2. Eastern Antarctica:

• The East Antarctica faces the Atlantic and the Indian Oceans.
• The Mt. Erebus in this region is an active volcano located in the Ross Island.

Question 3.
Great Barrier Reef and Artesian Basin.
Answer:
1. Great Barrier Reef:

• Great Barrier Reef is located in the north east of Australia.
• It is formed by the tiny coral polyps..
• It is about 2300 kms long.

2. Artesian Basin:

• The Artesian Basins are regions on the earth’s surface where water gushes out like a fountain.
• It is found in the arid and semi – arid parts of Queensland.
• It extents for 1.7 million square km.

VII. Give reasons:

Question 1.
Egypt is called the gift of the Nile.
Answer:

1. Nile is the life line of Egypt
2. Without Nile the Egypt would have been a desert
3. So Egypt in the gift of the Nile.

Question 2.
Deserts are found in the western margins of continents.
Answer:

1. Most of the world deserts are located in the western margins of continents in the subtropics because the prevailing winds in the tropics are tropical easterly winds.
2. The tropical easterly winds become dry by the time they reach the western margins of continent and so they bring no rainfall.

Question 3.
Antarctica is called the continent of scientists.
Answer:

1. Scientists of any country are free to conduct experiments and collect data from Antarctica.
2. Hence it is called ‘continent of Science’.

VIII. Answer in a paragraph each:

Question 1.
Give an account on mineral wealth of Australia.
Answer:

1. Minerals are the largest export item of Australia.
2. It contributes about 10 percent of country’s GDP.
3. Australia is the world’s leading producer of bauxite, limonite, rutile and zircon.
4. The Second largest producer of gold, lead, lithium, manganese ore and zinc, the third largest producer of iron ore and uranium and they fourth largest producer of black coal.
5. The coal belts of the country stretches from New Castle to Sydney on the South Eastern Coast.
6. Iron ores are found mainly in southern and Western Australia.
7. Petroleum and natural gas is obtained from Bass Strait and west of Brisbane.
8. Uranium is mined in northern territory at Ram jungle and Queensland.
9. Gold is mined in the western desert at Kalgoorlie and Koolgarlie.
10. Lead, Silver, Zinc, Manganese, Tungsten, Nickel and copper are also mined in parts of Australia.

Question 2.
Describe the flora and fauna of Antarctica
Answer:
Flaora and Fauna:

1. Since the temperature is below freezing point almost throughout the year, no major vegetation is found in this continent.
2. Simple plants like algae, mosses, liverworts, lichens and microscopic fungi can survive and grow in Antarctica.
3. Some algae live in the snow, while other plants grow on the coastal rocky land that is ice free.
4. A few species of plants, such as plankton, algae and mosses are seen in and around, Antarctica’s fresh and saltwater lakes.
5. Small red fish called krill are found in large shoals .It is the food for many warm blooded sea animals.
6. The blue whale is the largest animal which feeds on plankton. All these animals and birds have a thick layer of fat called blubber which helps them to withstand the cold condition.
7. Penguin birds in Antarctica cannot fly. They have webbed feet and flipper instead of wings. Small invertebrates are the only land animals which lives in the continent.

Question 3.
Name the physical divisions of Africa and explain any one.
Answer:
1. Africa consists of mixture of land forms such as mountains, plateaus and plains. The following are the 8 major physical divisions of Africa.

• Sahara
• Sahel
• Savanna
• The Great Rift Valley and the Great Lakes of Africa
• East African Highlands
• Swahili Coast
• The Congo Basin or Zaire Basin
• Southern Africa

2. Southern Africa.

• Most part of the Southern Africa is a plateau region.
• Drakensberg Mountain is found in the eastern portion of the escarpment.
• It extends from north east to south west for 1125 km.
• Its highest peak is.Thabana Ntlenyana (3482m).
• This region is covered with grasslands known as‘Veld’.
• Kalahari Desert lies in the south and Namib Desert is along the south -west shore of Africa.
• Kalahari Desert in this region is not actually a desert but, a bushy scrubland situated between the Orange and Zambezi Rivers.

XI. Map skill:

Question 1.
Mark the following on the outline map of Africa and Australia.
Answer:
Africa:
Equator, Atlas Mountain, Sahara, Eastern highlands, Mediterranean Sea, Atlantic Ocean, Indian Ocean, Suez Canal, Mount Kilimanjaro,

Australia:
Great Dividing Range , Great barrier reef, Tasmania, tropic of Capricorn, pacific ocean. Great Australian Sandy Desert. Indian ocean, Sydney, Canberra.

X. Activity:

Question 1.
Find out the hemisphere and season during December for the following countries.
Answer:

Question 2.
Label the name of the different states of Australia in the following map

Answer:

Samacheer Kalvi 8th Social Science Geography Chapter 2 Exploring Continents (Africa, Australia and Antarctica) Additional Questions

I. Choose the correct answer:

Question 1.
The second largest continent of the world is …………..
(a) Asia
(b) Africa
(c) Europe
(d) South Africa
Answer:
(b) Africa

Question 2.
The only continent through which Tropic of Capricorn and Tropic of Cancer pass is ………….. in Indian ocean took place in the year 2004.
(a) Asia
(b) Australia
(c) Africa
(d) Europe
Answer:
(c) Africa

Question 3.
Africa is located in all the ………….. hemisphere.
(a) three
(b) two
(c) four
(d) none of the above
Answer:
(c) four

Question 4.
Henry M. Stanley used the term ………….. to refer to Africa
(a) Land of rising sun
(b) Land of Thousand lakes
(c) Dark continent
(d) none of the above
Answer:
(c) Dark continent

Question 5.
The continent of Africa consists of ………….. countries.
(a) 48
(b) 54
(c) 36
(d) 60
Answer:
(b) 54

Question 6.
The term ‘Maghreb’ refers to ………….. of Africa.
(a) North Western countries
(b) West part
(c) Central part
(d) Eastern part
Answer:
(a) North Western countries

Question 7.
Sahara desert is located in the ………….. part of Africa.
(a) Eastern
(b) Western
(c) Southern
(d) Northern
Answer:
(d) Northern

Question 8.
The Mediterranean Sea and Atlantic ocean are separated by ………….. moutain.
(a) Atlas
(b) Himalayas
(c) Rocky
(d) None of the above
Answer:
(a) Atlas

Question 9.
The African Great Lakes consist of ………….. major lakes.
(a) 5
(b) 7
(c) 6
(d) 4
Answer:
(b) 7

Question 10.
Kalahari desert situated between the Orange and ………….. Rivers.
(a) Nile
(b) Congo
(c) Amazon
(d) Zambezi
Answer:
(d) Zambezi

Question 11.
Father of African rivers is …………..
(a) Cango
(b) Nile
(c) Niger
(d) Zambezi
Answer:
(b) Nile

Question 12.
Southern Africas ‘River of Life’ is …………..
(a) Cango
(b) Zambezi
(C) Nile
(d) Zaire
Answer:
(b) Zambezi

Question 13.
The Chief cash crop of Africa is …………..
(a) Cotton
(b) Jute
(c) Tea
(d) Sugarcane
Answer:
(a) Cotton

Question 14.
Australia’s largest physical division is …………..
(a) The Great Western Plateau
(b) The Central Low lands
(c) The Eastern High lands
(d) None of the above
Answer:
(a) The Great Western Plateau

Question 15.
Mt. Kosciuszko is located in the …………..
(a) Melbourne
(b) Perth
(c) New South Wales
(d) Adelaide
Answer:
(c) New South Wales

Question 16.
Tasmania gets rain throughout the year from …………..
(a) Trade winds
(b) Monsoon winds
(c) westerly winds
(d) None of the above
Answer:
(c) westerly winds

Question 17.
The Cash Crop of Australia is …………..
(a) Cotton
(b) Tea
(c) Wool
(d) Jute
Answer:
(c) Wool

Question 18.
Australia is highly dependent on ………….. transport.
(a) road
(b) train
(c) air
(d) water
Answer:
(a) road

Question 19.
There is no native population in …………..
(a) Asia
(b) Africa
(c) Australia
(d) Antarctica
Answer:
(d) Antarctica

Question 20.
Artesian basins are common in …………..
(a) Africa
(b) Australia
(c) Antarctica
(d) South America
Answer:
(b) Australia

II. Fill in the blanks:

1. The second most populous continent after Asia is …………..
2. In Africa the Prime Meridian Passes near ………….. the capital of Ghana.
3. The major island of Africa is ……………
4. Sahara is one of the largest ………….. in the world.
5. ………….., an extinct volcano in chad, is the highest point in the sahara.
6. Sahara’s deepest point is ………….. in Egypt.
7. Sahel means ……………
8. In Africa tropical dry grasslands are known as …………..
9. One of the largest plains in Savanna is …………..
10. ………….. plain is called the open Air Zoo.
11. The largest fresh water body in Africa is …………..
12. The first largest fresh water is ………….. in USA.
13. Lake Victoria is the source of river …………..
14. The longest and deepest fresh water lake in the world is ……………
15. Swahili coast is located along the shores of ……………
16. The world’s first largest river basin is ………….. in South America.
17. The second largest river basin in the world is the ………….. in Africa.
18. Southern Africa region is c covered with grasslands known as ……………
19. The Gift of the Nile is ……………
20. The longest river in the world is ……………
21. The world famous waterfall Victoria is formed by the river ……………
22. Southern Africa’s ‘River of Life’ is river ……………
23. A hot and dry dusty local wind blowing from the Sahara desert to Guinea coast is called …………..
24. A hot local wind blowing from Sahara to Mediterranean Sea is called …………..
25. Ghana is the Chief Producer of ……………
26. The most populous country of Africa is …………..
27. Australia is the largest ………….. and smallest ………….. in the world
28. Australia was discovered by …………. an English Seaman in 1770 .
29. The Tropic of ………….. cuts the Australia continent into two equal halves.
30. The capital of Australia is ……………
31. ………….. is the largest monolith rock in the world.
32. The largest desert in Australia is the ……………
33. The largest Salt Lake ………….. lies in the central low lands of Australia.
34. The Eastern Highlands are also known as ………….. in Australia.
35. The Great. Barrier Reef is formed by the ……………
36. The longest river in Australia is ……………
37. The plants and trees in Australia are called ……………
38. The people who work in the sheep station in Australia are known as ……………
39. The indigenous people of Australia are called …………..
40. Tasmania is known as the ………….. Island.
41.  ………….. are rearing in Southern Australia.
42.  The densely populated region is ………….. part of Australia.
43. The Mt. Erebus an active volcano is located in the ………….. Island.
44. The largest piece of ice on the surface of Earth is …………..
45. The largest glacier in the world in ………….. located in …………..

Answers:

1. Africa
2. Accra
3. Antarctica
4. hot deserts
5. Mount Koussi
6. Qattara
7. broder or margin
8. savanna
9. Serengeti
10. Serengeti
11. Lake Victoria
12. Lake superior
13. Nile
14. Tanganyika
15. East Africa
16. Amazon
17. Congo
18. Veld
19. Egypt
20. River Nile
21. Zambezi
22. Zambezi
23. Harmattan
24. Sirocco
25. Cocoa
26. Nigeria
27. island/continent
28. Captain James Cook
29. Capricorn
30. Canberra
31. Ayers rock or Uluru
32. Great Victoria Desert
33. Lake Eyre
34. Great Dividing Range
35. Tiny coral polyps
36. River Murray
37. Xerophytes
38. Jackroos
39. Aborigines
40. Apple
41. Merino
42. Southeastern
43. Ross
44. Antarctica
45. Lambert glacier, Antarctica

III. Match the following:

Question 1.

1. Dark Continent – a) Explorer
2. David Livingstone – b) Evergreen Forest
3. Atlas mduntain – c) Sheep rearing
4. Congo Basin – d) Africa
5. Karoo – e) Young fold mountain

Answer:

1. d
2. a
3. e
4. b
5. c

Question 2.

1. Captain James Cook – a) New South Wales
2. Uluru – b) Australian river
3. Mt. Kosciuszko – c) Swamp forests
4. Lachlan – d) Monolitic rock
5. Melaleuca – e) Australia

Answer:

1. e
2. d
3. a
4. b
5. c

Question 3.

1. Antarctica – a) largest animal
2. White continent – b) Largest Research station
3. Blue whale – c) India
4. Mcmurdo – d) Continent of Science
5. Bharathi – e) Antarctica

Answer:

1. d
2. e
3. a
4. b
5. c

IV. Let us learn :

Question 1.
Assertion (A) : H.M. Stanley called Africa Dark continent.
Reason (R) : In the beginning the interior of Africa was largely unknown to people.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true and R is not the correct explanation of A
(c) A is true but R is false
(d) R is true but A is false
Answer:
(a) Both A and R are individually true and R is the correct explanation of A

Question 2.
Assertion (A) : The great Barrier Reef is one of the natural wonders of the world.
Reason (R) : The Great Barrier Reef is formed by the tiny coral polyps.
(a) Both A and R are individually true and R is the correct explanation of A
(b) Both A and R are individually true and R is not the correct explanation of A
(c) A is true but R is false
(d) R is true but A is false
Answer:
(a) Both A and R are individually true and R is the correct explanation of A

V. Answer in brief :

Question 1.
Explain the term‘Maghreb’.
Answer:
The north-western African countries of Morocco, Algeria, Libya, Mauritania and Tunisia are collectively called ‘Maghreb’, which means west in Arabic language.

Question 2.
Write a note on Atlas Mountains.
Answer:

1. Atlas Mountain lies in the north- west of Africa.
2. It is a young fold mountain.
3. It separates the Mediterranean sea and Atlantic ocean.
4. The highest point is Mount Toubkal (4167m).

Question 3.
Where do we find Savanna grasslands in Africa?
Answer:

1. Savanna grassland is found in the regions just north and south of the rain forests that lie along the equator.
2. Trees are the main features of the landscape in some parts of the savanna, while tall grass covers the other areas.
3. The Serengeti Plain is one of the largest plains in Savanna.
4. This is called the ‘Open Air Zoo’.

Question 4.
Nile is known as the Father of African Rivers. Give reasons.
Answer:

1. River Nile is known as the Father of African Rivers.
2. It is the largest river in the world with a length of 6650 km.
3. White Nile and the Blue Nile join together to form the River Nile at Khartoum, in Sudan.
4. It flows towards and drains into the Mediterranean-sea.

Question 5.
Write about the animals of Africa.
Answer:

1. There are over one million species of animals in Africa including both the heaviest (elephants) and the tallest (giraffes) land animals on the earth.
2. White Rhinoceros, Western Green Mamba, Zebra, African Elephants, chimpanzee, gorilla, Hippopotamus and Giraffe are the major animals of Africa.
3. Bonobo, Wild Dogs, hyena and Lemur are the typical animals of Africa.

Question 6.
Name the major tribes of Africa.
Answer:
Afar, Fatwa, Bushmen, Dinka, Masai, Pygmies, Zulu, Tswan, and Efe are the major tribes of Africa.

Question 7.
Mention the political division of Australia.
Answer:
There are six states and two Union Territory in Australia They are:

1. New South Wales
2. Queensland
3. South Australia
4. Tasmania
5. Victoria
6. Western Australia
7. Northern Territory
8. Capital Territory (Canberra).

Question 8.
Mention the important cities of Australia.
Answer:

1. Canberra is the capital of Australia.
2. Sydney, Brisbane, Adelaide, Hobart, Melbourne, Perth and Darwin are the other important cities of Australia.

Question 9.
Why is Ayers rock one of the natural wonders of Australia?
Answer:

1. Ayers rock or Uluru is the largest monolith rock in the world.
2. It is found in the central part of The Great Western Plateau region.
3. It is 863 meters high above the sea level.
4. The pointed limestone pillars called Pinnacles are common in this region.

Question 10.
What is meant by Xerophytes?
Answer:

1. The plants and trees in Australia are adapted to dry conditions.
2. They can survive for long period without water.
3. They are called Xerophytes.

Question 11.
Write about the fauna of Australia.
Answer:

1. Australia has almost 400 mammal species and about 140 species of marsupials.
2. These are the animals that carry their young ones in their pouches.
3. Kangaroo is the national animal of Australia.
4. Koala, platypus Wallaby and Dingo are the other important animals of Australia.
5. The bird species like the laughing kookaburra, emu, and rainbow lorikeet are the major birds of Australia.

Question 12.
What are Merino sheep.
Answer:

1. In Australia sheep farming is common in the temperate grassland.
2. Merino sheep are rearing in southern Australia, Tasmania, Victoria and New South Wales.
3. Sheep industry is a well developed industry in Australia.
4. The wool is described as the ‘Cash Crop’ in Australia.

Question 13.
Mention the important industries A frica.
Answer:

1. Food and beverage manufacturing industry is the primary industry in Australia.
2. Finance, ship building, information and technology, mining, insurance, aviation and telecommunication industries are the other important industries.

Question 14.
Mention the living creatures of Antarctica Continent.
Answer:

1. Small red fish called krill are found in large shoals .It is the food for many warm blooded sea animals.
2. The living creatures of this region are includes whales, seals, walrus and sea birds like penguins, albatross, polar Skua and Stout.
3. The blue whale is the largest animal which feeds on plankton.

VI. Distinguish between:

Question 1.
River Congo and River Niger
Answer:
1. River Congo:

• It is the second largest river of Africa.
• Its rises in the highlands of North Eastern Zambia .
• Its length is about 4700km.
• Drains into the Atlantic Ocean

2. River Niger:

• It is one of the major rivers in West Africa.
• It rises from the highlands of Guinea.
• It flows for about 4184 km.
• Drains into the Gulf of Guinea on the Atlantic Ocean.

Question 2.
Equatorial climate and Mediterranean climate (Africa).
Answer:
1. Equatorial climate (Africa):

• It is found in the equatorial region covering the Congo River basin and east African highlands.
• Temperature and rainfall are high all the year round in this region.

2. Mediterranean climate (Africa):

• It is found in the north-western and south western tips of Africa.
• These regions get rainfall in winters while in summers it is hot and dry.

Question 3.
Waterways and Airways (Africa).
Answer:
1. Waterways (Africa):

• Africa has trade routes between Asia and Australia in the east, Europe in the north and America in’the west.
• The major sea ports of Africa are Durban, Dar es Salaam and Mogadishu on the Indian Ocean, Port Said, and Alexandria, on the Mediterranean Sea, Cape Town, Algiers and Abidjan on the Atlantic Ocean.

2. Airways (Africa):

• They connect the capital cities of Africa and the other parts of the world.
• The major international airports of the continent are Cairo, Johannesburg, Nairobi, Dakar, Addis- Ababa, Casablanca, Durban, Douala and Logos.

VII. Give Reasons :

Question 1.
Kilimanjaro summit will be ice -free by 2025.
Answer:

1. The glaciers on the top of Kilimanjaro have been disappearing since 20th centuries.
2. If this trend continues. Kilimanjaro summit will be .ice -free by 2025.

Question 2.
The name of Swahili to the people of Swahili Coast.
Answer:

1. Swahili Coast region extents from Somalia to Mozambique.
2. It was a region where the Africans and Arabs mixed to create a unique culture referred to as Swahili Culture.
3. People of this coast are also called as ‘Swahili’.

Question 3.
Roadways and Railways in Africa are poorly developed.
Answer:

1. Roadways and Railways in Africa are poorly developed due to the presence of many barriers.
2. It is very difficult to lay the roads and rails across the deserts and the dense forests.
3. South Africa, Kenya, Egypt, Libya. Morocco and Nigeria have roadways and railways to some extent.

Question 4.
Australia was the last continent to be discovered.
Answer:

1. Australia was the last of all the continents to be discovered.
2. It was due to its remoteness.

Question 5.
Antarctica is the coldest continent.
Answer:

1. Antarctica is the coldest continent in the world.
2. It is located in the polar region.
3. It has a permanent cover of ice.

Question 6.
Antarctica is the only white continent.
Answer:

1. Antarctica is the only continent called white continent.
2. It has a permanent cover of ice.
3. In some places its ice cap is 4,000 metres deep.

Question 7.
The extraction of minerals does not take place in Antarctica.
Answer:

1. The international agreement on the continent of Antarctica does not permit the extraction of minerals.
2. Hence the extraction of minerals does not take place.

VIII. Answer in a paragraph each :

Question 1.
Write about the mineral wealth of Antarctica Continent.
Answer:

1. Scientific studies show that the Antarctic continent is to be rich in gold, platinum, nickel, copper and petroleum.
2. Traces of chromium, lead, molybdenum, tin, uranium, and zinc are also seen.
3. The possible resources of this region also include silver, platinum, iron ore, cobalt, manganese and titanium.
4. Coal and hydrocarbons have been explored in minimal non-commercial quantities.

Question 2.
Explain the term Aurora
Answer:

1. A natural Curtain of combination of bright pink, red and green color light that appears in the sky near the north and south magnetic poles is called Aurora.
2. The effect is caused by the interaction of charged particles from the sun with atoms in the upper atmosphere.
3. It is also called Aurora Australis or Southern Lights in the South Pole and Aurora Borealis or Northern Lights in the North Pole.
4. These amazing colours appear in the earth’s sky, especially in the high latitudinal countries like Alaska in the north and New Zealand of Falkland in the south.

Question 3.
What type of climatic Pattern is experienced by Australia?
Answer:

1. Australia contains the second largest area of extremely arid land in the world.
2. The Tropic of Capricorn divides the Australia into two equal parts.
3. The Northern half is in the warm tropical zone and the southern half is in the cool temperate zone.
4. The north coastal region experiences monsoon type of climate and there is a heavy rainfall during summer.
5. The east coastal region receives good rainfall from south east trade wind.
6. The hot desert climate extends from central lowlands to western shores.
7. The rainfall in this region is less than 25cm per annum.
8. Mediterranean type of climate prevails in the southern tip of Australia in the region around Perth and Adelaide.
9. Tasmania gets rain throughout the year from westerly winds.

Question 4.
Explain the location and size of Africa.
Answer:

1. Africa is the second largest and second most populous continent after Asia.
2. It stretches from 37°21 ’North latitude to 34° 51 ’ South latitude and from 17°33’ West longitude to 51 °27 ’ East longitude.
3. It spreads over an area of about 30.36 million square kilometres (20.2% of the world’s land area).
4. The equator passes through the middle of Africa and cuts into two equal halves.
5. It is the only continent through which the major latitudes such as Tropic of Cancer, Equator and Tropic of Capricorn pass.
6. Its north-south extent is 7623 km and east-west extent is 7260 km.
7. The Prime Meridian passes this continent.
8. Africa is located in all the four hemispheres.

Samacheer Kalvi 8th Social Science Geography Chapter 2 Exploring Continents (Africa, Australia and Antarctica) Intext activity

Question 1.
On the outline map of Africa draw the courses of main rivers and name them.
Answer:

Question 2.
There are eight deserts in Australia. List them out with the help of Atlas.
Answer:

1. Central Desert
2. Gibson Desert
3. Great Sandy Desert
4. Great Victoria Desert
5. Little Sandy Desert
6. Simpson Desert
7. Strzelecki Desert
8. Tanami Desert

Students can Download Maths Chapter 1 Life Mathematics Ex 1.1 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 1 Chapter 1 Life Mathematics Ex 1.1

Question 1.
Fill in the blanks:

Question (i)
If 30% of x is 150, then x is ………….
Answer:
500
Hint:
Given 30% of x is 150

Question (ii)
2 minutes is ………… % to an hour.
Answer:
3\(\frac{1}{3}\)%
Hint:
Let 2 min be x% of an hour
and 1 hr = 60 min
x% = \(\frac{2}{60}\) x 100 = \(\frac{200}{3}\) = \(\frac{10}{3}\) = 3\(\frac{1}{3}\)
x = 3\(\frac{1}{3}\)

Question (iii)
If x % of x = 25, then x = …………
Answer:
50
Hint:
Given that x % of x is 25
∴ \(\frac{x}{100}\) = 25
x² = 25 x 100 = 2500
∴ x = \(\sqrt{2500}\) = 50

Question (iv)
In a school of 1400 students, there are 420 girls. The percentage of boys in the school is ………….
Answer:
70
Hint:
Given total number of students in school = 1400
Number of girls in school = 420
Number of boys in school = 1400 – 420 = 980

% of boys = 70%

Question (v)
0.5252 is ………….. %.
Answer:
52.52%
Hint:
Given a number, and to express as a percentage, we need to multiply by 100
∴ to express 0.5252 as percentage, we should multiply by 100
∴ 0.5252 x 100 = 52.52%

Question 2.
Rewrite each underlined portion using percentage language.

Question (i)
One half of the cake is distributed to the children.
Answer:
Answer:
50% of the cake is distributed to the children
Hint:
One half is nothing but \(\frac{1}{2}\) as percentage, we need to multiply by 100
\(\frac{1}{2}\) x 100 = 50%

Question (ii)
Aparna scored 7.5 points out of 10 in a competition.
Answer:
Aparna scored 75% in a competition
Hint:
7.5 points out of 10 is \(\frac{7.5}{10}\) = 0.75
For percentage, we need to multiply by 100
∴ We get 0.75 x 100 = 75%

Question (iii)
The statue was made of pure silver.
Answer:
96% students participated in sports
Hint:
Pure silver means there are no other metals
so, 100 out of 100 parts is made of silver = \(\frac{100}{100}\)
∴ to express as percentage, \(\frac{100}{100}\) x 100% = 100%

Question (iv)
48 out of 50 students participated in sports
Answer:
96% students participated in sports
Hint:
48 out of 50 students in fraction form is \(\frac{48}{50}\).
As a percentage, we need to multiply by 100

Question (v)
Only 2 persons out of 3 will be selected in the interview
Answer:
Only 66\(\frac{2}{3}\)% persons will be selected in the interview.
Hint:
2 out of 3 in fraction form is \(\frac{2}{3}\) to express as percentage, we need to multiply by 100
\(\frac{2}{3}\) x 100 = \(\frac{200}{3}\) = 66\(\frac{2}{3}\)%

Question 3.
48 is 32% of what number?
Solution:
Let the number required to be found be ‘x’
Given that 32% of x is 48

Question 4.
A bank pays ₹ 240 as interest for 2 years for a sum of ? 3000 deposited as savings. Find the rate of interest given by the bank.
Solution:
The formula for simple interest is given by
Interest (I) = \(\frac{PxRxT}{100}\) 100
Where P is principal amount; R is rate of interest in percentage; t is time period Substituting given values in formula, we get
P = 3000, t = 2 yrs, I = Rs 240

Question 5.
A Welfare Association has a sports club where 30% of the members play cricket, 28% play volleyball, 22% play badminton and the rest play indoor games. If 30 member play indoor games.

1. How many members are there in the sports club?
2. How many play cricket, volleyball and badminton?

Solution:
Given data
Members who play Cricket = 30% …..(1)
Members who play Vollyball = 28% …..(2)
Members who play Batminton = 22% ……(3)
Members who play outdoor games = (1) + (2) + (3) = 30
Members who play indoor games = 100 – 80 = 20%
Also given 30 members play indoor games
Let total no of members be ‘x’
∴ \(\frac{30}{x}\) = 20
∴ x = \(\frac{30×100}{20}\) = 15

1. Total number of members is 150

2. Members who play Cricket = 30% of total = \(\frac{30}{100}\) x 150

Question 6.
What is 25% of 30% of 400?
Solution:
Required to find 25% of 30% of 400

Question 7.
If the difference between 75% of a number and 60% of the same number is 82.5, then find 20% of the number.
Solution:
Given that 75% of number less 60% of number is 82.5. Let the number be ‘x’
∴ \(\frac{75}{100}\) × x = 82.5
∴ 0.75 – 0.6.60x = 82.5
∴ 0.15x = 82.5
∴ x = \(\frac{82.5}{0.15}\) = \(\frac{8250}{15}\) = 550
Required to find 20% of number ie 20% of x.

Question 8.
If a car is sold for ₹ 2,00,000 from its original price of? 3,00,000 find the percentage for decrease in the value of the car.

Solution:
Original price of car = ₹ 3,00,000
actual selling price of car = ₹ 2,00,000
Decrease in amount from original = 3,00,000 – 2,00,000 = 1,00,000

Question 9.
A number when increased by 18% gives 236. Find the number.
Solution:
Let the number be x. Given that when it is increased by 18%, we get 236.
x + \(\frac{18}{100}\) = 236
\(\frac{100x+18x}{100}\) = 236
\(\frac{118}{100}\)x = 236
The number = x = \(\frac{236×100}{118}\) = 200

Question 10.
A number when decreased by 20% gives 80. Find the number.
Solution:
Let the number be x. Given that when it is increased by 20% we get 80.

Question 11.
A number is increased by 25% and then decreased by 20%. Find the change in that number.
Solution:
Method 1:
Let the number be x. First it is increased by 25%

Method 2:
[to understand, let us assume that number is 100]
So, first when we increase by 25%, we get

We get back 100 ⇒ No change

Question 12.
If the numerator of a fraction is increased by 25% and the denominator is increased by 10%, it becomes \(\frac{2}{5}\). Find the original fraction.
Solution:
Let the fraction be \(\frac{N}{D}\) where N is numerator & D is denominator
It is given that numerator is include by 25%

Question 13.
A fruit vendor bought some mangoes of which 10% were rotten. He sold 33 \(\frac{1}{3}\)% of the rest. Find the total number of mangoes bought by him initially, if he still has 240 mangoes with him.

Solution:
Let the number of mangoes bought by fruit seller initially be x.
Given that 10% of mangoes were rotten
∴ Number of rotten mangoes = \(\frac{10}{100}\) × x
Number of good mangoes = x – no. of rotten mangoes
= x – \(\frac{10}{100}\)x = \(\frac{100x-10x}{100}\) = \(\frac{90}{100}\)x …(1)
Number of mangoes sold = 33\(\frac{1}{3}\)% of good mangoes = \(\frac{100}{3}\)%
∴ Mangoes sold = \(\frac{100}{3}\) x \(\frac{90}{100}\)x × \(\frac{1}{100}\) = \(\frac{30}{100}\)x
Number of mangoes remaining = No. of good mangoes – No. of mangoes sold
From (1) and (2)

Question 14.
A student gets 31% marks in an examination but fails by 12 marks. If the pass percentage is 35%, find the maximum marks of the examination.
Solution:
Let the maximum marks in the exam be ‘x’. Pass percentage is given as 35%
∴ Pass mark = \(\frac{35}{100}\) × x = \(\frac{35}{100}\)x
Student gets 31 % marks = \(\frac{31}{100}\) × x = \(\frac{31}{100}\)x
But student fails by 12 marks → meaning his mark is 12 less than pass mark.
∴ \(\frac{31}{100}\)x = \(\frac{35}{100}\)x – 12
∴ \(\frac{35}{100}\)x – \(\frac{31}{100}\)x = 12
∴ \(\frac{35x-31x}{100}\) = 12 ⇒ \(\frac{4x}{100}\) = 12
∴ \(\frac{12×100}{4}\) = 300

Question 15.
The ratio of boys and girls in a class is 5:3. If 16% of boys and 8% of girls failed in an examination, then find the percentage of passed students.
Solution:
Let number of boys be ‘6’ and number of girls be ‘g’
Ratio of boys and girls is given as 5:3
b:g = 5:3 ⇒ \(\frac{b}{g}\) = \(\frac{5}{3}\) …..(A)
Failure in boys = 16% = \(\frac{16}{100}\) x b = \(\frac{16b}{100}\)
Failure in girls = 8% = \(\frac{8}{100}\) x g = \(\frac{8g}{100}\)
Pass in boys = 100 – 16% = 84% \(\frac{84}{100}\)b …..(1)
Pass in girls = 100 – 8% = 92% = \(\frac{92}{100}\)g
From A, we have \(\frac{b}{g}\) = \(\frac{5}{3}\), = adding 1 on both sides, we get
\(\frac{b}{g}\) + 1 = \(\frac{5}{3}\) + 1
\(\frac{b+g}{g}\) = \(\frac{5+3}{3}\) = \(\frac{8}{3}\)
∴ g = \(\frac{3}{8}\)(b + g)
Similarly b = \(\frac{5}{8}\)(b + g)
Total pass = Pass in girls + Pass in boys
= (1) + (2) = \(\frac{84}{100}\)b + \(\frac{92}{100}\)g

Objective Type Questions

Question 16.
12% of 250 litres is the same as ………. of 150 liters
(a) 10%
(b) 15%
(c) 20%
(d) 30%
Answer:
(c) 20%
Hint:
12% of 250 = \(\frac{12}{100}\) x 250 = 30 lit
Percentage : \(\frac{30}{150}\) x 100 = 20%

Question 17.
If three candidates A, B and C is 3 in a school election got 153, 245 and 102 votes respectively, the percentage of votes for the winner is ……..
(a) 48%
(b) 49%
(c) 50%
(d) 45%
Answer:
(b) 49%
Hint:
Candidate 1: 153
Candidate 2: 245 – winner [as maximum votes]
Candidate 3: 102
Total votes = 1 + 2 + 3 = 153 + 245 + 102 = 500

Question 18.
15% of 25% of 10000 = ………..
(a) 375
(b) 400
(c) 425
(d) 475
Answer:
(a) 375
Hint:
15% of 25% of 10000 is
First let us do 25% of 10,000, which is

Next 15% of the above is \(\frac{15}{100}\) x 2500 = 375

Question 19.
When 60 is subtracted from 60% of a number to give 60, the number is –
(a) 60
(b) 100
(c) 150
(d) 200
Answer:
(d) 200
Hint:
Let the number be ‘x’.
60% of the number is \(\frac{60}{100}\) × x = \(\frac{60x}{100}\)
Given that when 60 is subtracted from 60%, we get 60
i.e \(\frac{60}{100}\)x – 60 = 60
∴ \(\frac{60}{100}\)x = 60 + 60 = 120
∴ x = \(\frac{120×100}{60}\) = 200

Question 20.
If 48% of 48 = 64% of x, then x =
(a) 64
(b) 56
(c) 42
(d) 36
Answer:
(d) 36
Hint:
Given that 48% of 48 48 = 64% of x

You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 1 Chapter 9 Introduction to the Information Age

Samacheer Kalvi 8th Science Solutions Introduction to the Information Age

I. Choose the correct answers

Question 1.
Who is the father of computer?
(a) Martin Luther King
(b) Graham Bell
(c) Charlie Chaplin
(d) Charles Babbage
Answer:
(d) Charles Babbage

Question 2.
Which one of the following is an output device?
(a) Mouse
(b) Keyboard
(c) Speaker
(d) Pendrive
Answer:
(c) Speaker

Question 3.
Which one of the following is an input device?
(a) Speaker
(b) Keyboard
(c) Monitor
(d) Printer
Answer:
(b) Keyboard

Question 4.
Pen drive is ……………. device.
(a) Output
(b) Input
(c) Storage
(d) Connecting cable
Answer:
(c) Storage

Question 5.
Fifth generation computer has ……………… Intelligence.
(a) Transistors
(b) Integrated Circuits
(c) Microprocessor
(d) Artificial Intelligence
Answer:
(d) Artificial Intelligence

II. Match the following

Question 1.

Column A		Column B
1.	Keyboard	(a)	RAM
2.	Fourth generation Computer	(b)	Input device
3.	Hardware	(c)	Integrated Circuits
4.	Third generation Computer	(d)	Drawing tools
5.	Application Software	(e)	Microprocessor

Answer:

1. b
2. e
3. a
4. c
5. d

III. Give short answer

Question 1.
What is a Computer?
Answer:
A Computer is an electronic machine that accepts data, stores and processes data into information.

Question 2.
Name the parts of a computer.
Answer:
Parts of a Computer:

1. Input Unit
2. Central Processing Unit (CPU)
3. Output Unit

Question 3.
What is Hardware and Software?
Answer:
Hardware:

1. Hardware is the parts of a computer which we can touch and feel.
2. Hardware includes Input and Output devices, Cabinet, Hard Disk, Mother Board, SMPS, CPU, RAM, CD Drive and Graphics Card.

Software:

1. Hardware is lifeless without software in a computer.
2. Softwares are programmed and coded applications to process the input information.
3. The software processes the data by converting the input information into coding or programmed language.

Samacheer Kalvi 8th Science Solutions Introduction to the Information Age Additional Questions

I. Choose the correct answer

Question 1.
The main component used for the first generation computers is ……………….
(a) Transistors
(b) Integrated Circuits
(c) Microprocessor
(d) Vacuum Tubes
Answer:
(d) Vacuum Tubes

Question 2.
Artificial Intelligence is the main component of ……………… generation computers.
(a) first
(b) Fifth
(c) Third
(d) Fourth
Answer:
(b) Fifth

Question 3.
Computer performs tasks determined by …………….
(a) Programs
(b) Hardware
(c) Keyboard
(d) Mouse
Answer:
(a) Programs

Question 4.
Light pen is a …………….. device.
(a) Input
(b) Output
(c) Software
(d) None of these
Answer:
(a) Input

Question 5.
……………….. of the mouse is used to move the page up and down.
(a) Scroll Ball
(b) Pointer
(c) Right Click
(d) Left Click
Answer:
(a) Scroll Ball

II. Match the following

Question 1.

i	First generation	(a)	Micro processor
ii	Second generation	(b)	Artificial intelligence
iii	Third generation	(c)	Transistors
iv	Fourth generation	(d)	Integrated circuits
v	Fifth generation	(e)	Vacuum tubes

Answer:

i. e
ii. c
iii. d
iv. a
v. b

Question 2.

i	Joy stick	(a)	Personal computer
ii	Compact disk	(b)	LINUX
iii	Tablet	(c)	Input device
iv	SMPS	(d)	Hardware
v	Operating system	(d)	Memory unit

Answer:

i. c
ii. e
iii. a
iv. d
v. b

Question 3.

i	Programming language	(a)	Specific purposed software
ii	System utilities	(b)	General purpose software
iii	Spread sheet	(c)	Developing software
iv	Billing system	(d)	System management program

Answer:

i. c
ii. d
iii. a
iv. b

III. Short Answer

Question 1.
Differentiate input and output device.
Answer:

S.No	Input device	Output device
1.	The hardware devices that are used to input data are called input devices.	The output unit converts, the command received by the computer in the form of binary signals into easily understandable characters.
2.	Keyboard, Mouse, Scanner, Bar code reader, Microphone- Mic, Web camera, Light Pen, Joy stick is some of the input devices.	Monitor, Printer, Speaker, scanner are some of the output devices.

Question 2.
What is a CPU?
Answer:
CPU is the brain of the Computer. The data is processed in the CPU. Th e CPU has namely three parts.

1. Memory Unit
2. Arithmetic Logic Unit (ALU)
3. Control Unit.

Question 3.
What is control unit?
Answer:
The control unit controls the functions of all the parts of the computer.

Question 4.
Write a note on arithmetic logic unit.
Answer:
Arithmetic and Logic unit performs all the arithmetic computations like addition, subtraction, multiplication and division.

Question 5.
Write briefly about memory unit.
Answer:

1. The memory unit in the computer saves all data and information temporarily.
2. We can classify memory unit into two types namely primary and secondary memory.
3. Memory can be expanded externally with the help of Compact Disk (CD), Pendrive, etc.

Question 6.
Mention the classification of computers.
Answer:
The computers can be classified based on their design, shape, speed, efficiency, working of the memory unit and their applications.

1. Mainframe Computer
2. Mini Computer
3. Micro or Personal Computer
4. Super Computer

Question 7.
What are the types of software?
Answer:
The software is divided into two types based on the process. They are

1. System Software (Operating System)
2. Application software

Question 8.
Give some information on system software.
Answer:

1. System Software (Operating system) is software that makes the hardware devices to process the inputted data and to display the result on the output devices like Monitor.
2. Without the operating systems, computer cannot function on its own.
3. Some of the popular operating system are Linux, Windows, Mac, Android etc.

Question 9.
Write a note on application software.
Answer:

1. Application software is a program or a group of programs designed for the benefit of end user to work on computer.
2. The application programs can be installed in the hard disk for the usage on a particular computer.
3. This type of application program completes one or more than two works of the end user.
4. The following are the examples of application program : Video player, Audio player, Word processing software, Drawing tools, Editing software, etc.

You can Download Samacheer Kalvi 8th Science Book Solutions Guide Pdf, Tamilnadu State Board help you to revise the complete Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Science Solutions Term 2 Chapter 7 Digital Painting

Samacheer Kalvi 8th Science Digital Painting Text Book Exercises

I. Choose the correct answer

Question 1.
Tux paint software is used to ……………..
(a) Paint
(b) Program
(c) Scan
(d) PDF
Answer:
(a) Paint

Question 2.
Which toolbar is used for drawing and editing controls in tux paint software?
(a) Left Side: Toolbar
(b) Right side : Toolbar
(c) Middle : Tool bar
(d) Bottom : Tool bar
Answer:
(a) Left Side : Toolbar

Question 3.
What is the shortcut key for undo option?
(a) Ctrl + Z
(b) Ctrl + R
(c) Ctrl + Y
(d) Ctrl + N
Answer:
(a) Ctrl + Z

Question 4.
Tux Math software helps in learning the ……………….
(a) Painting
(b) Arithmetic
(c) Programming
(d) Graphics
Answer:
(b) Arithmetic

Question 5.
In Thx Math, Space cadet option is used for ………………
(a) Simple addition
(b) Division
(c) Drawing
(d) Multiplication
Answer:
(a) Simple addition

II. Answer the following Questions

Question 1.
What is Tux Paint?
Answer:
Tux Paint is a free drawing program designed for young childreh.

Question 2.
What is the use of Text Tool?
Answer:
Text tool is used to type texts.

Question 3.
What is the Shortcut key for Save option?
Answer:
Ctrl + S

Question 4.
What is Tux Math?
Answer:
Tux Math is an open source arcade – style video game for learning arithmetic.

Question 5.
What is the use of Ranger?
Answer:
Ranger is used to do addition, subtraction, multiplication and division to ten.

Samacheer Kalvi 8th Science Digital Painting Additional Questions

I. Choose the correct answer.

Question 1.
Which tool is used to open an existing file?
(a) Line
(b) Open
(c) New
(d) Undo
Answer:
(b) Open

Question 2.
What is the shortcut key for print option?
(a) Ctrl + S
(b) Ctrl + O
(c) Ctrl + P
(d) Ctrl + Y
Answer:
(c) Ctrl + P

Question 3.
In tux paint scout option is used for ………………
(a) Simple addition
(b) Addition and subtraction to ten
(c) Division
(d) Multiplication
Answer:
(b) Addition and subtraction to ten

Question 4.
Which tool is used to cancel a command given earlier?
(a) Quit
(b) magic
(c) eraser
(d) undo
Answer:
(d) undo

Question 5.
Which tool is like a rubber stamps or stickers?
(a) text
(b) stamp
(c) eraser
(d) magic
Answer:
(b) stamp

II. Fill in the Blanks

1. When Tux paint first loads, a ………………… screen will appear.
2. The ………………… tool helps us to draw freehand drawings.
3. The ………………… tool is used to draw lines.
4. ………………… tool has a set of special tools.
5. Clicking the ………………… button will start a new drawing.

Answer:

1. title / credits
2. paint brush
3. line
4. Magic
5. New

III. Question and answers

Question 1.
What is the use of shapes tool?
Answer:
Shape tool is used to draw some simple filled and un-filled shapes.

Question 2.
What is play Arcade Game?
Answer:
This option is used to select and play one of the four open ended “arcade style” games.

Question 3.
Which tool is used to closed Tux Paint window?
Answer:
Quit tool is used to close Tux Paint window.

Question 4.
What is the use of selector?
Answer:
Selector display the options associated with the specific tool.

Question 5.
What is help area?
Answer:
Help area is in the bottom of the screen. It provides tips and other information while you draw.

Question 6.
What is magic tool?
Answer:
Magic tool is a set of special tools, selecting one of the ‘magic’ effects from the selector situated in the right side. This tool provides countless number of special visual effects if it is used in various combination with other tools.

IV. Give Long answers

Question 1.
What are the short keys in computers?
Answer:

Tool Name	Keyboad Shortcut Key
New	Ctrl + N
Open	Ctrl + O
Save	Ctrl + S
Print	Ctrl + P
Quit	Esc
Undo	Ctrl + Z
Redo	Ctrl + Y

Students can Download Maths Chapter 4 Information Processing Ex 4.3 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.3

Question 1.
Choose the correct answers:

Question (i)
In questions A and B, there are four groups of letters in each set. Three of these sets are like in some way while one is different. Find the one which is different.
A. (a) C R D T (b) A P B Q (c) E U F V (d) G W H X
B. (a) H K N Q (b) I L O R (c) J M P S (d) A D G J
Answer:
A. (a) C R D T (b) A P B Q (c) E U F V (d) G W H X
Hint:
The four groups of letters are
CRDT APBQ EUFV GWHX
The above can be written as

We find that when we take 1st & 3rd letter & 2nd & 4th letter as 2 pairs, the 3rd letter is the next letter alphabetically to the 1st letter.
Similarly the 4th letter is alphabetically the next letter of the 2nd letter.
i.e CD, AB, EF, GH & PQ, UV, WX
Only in CRDT, we have T instead of ‘S’. So,
Answer:
in CRDT ⇒ Option (a)

B. The four groups of letters are
HKNQ ILOR JMPS ADGI
If we notice, we find that 2 letters are missing in the sequence, ie.
H_IJK_LMN_OPQ I_JKL_MNO_PQR
L_KLM_NOP_QRS A_BCD_EFG_HI
We find that only in ADGI, the difference is only one letter between G & I.
Hence it is the odd one out.

Question (ii)
A group of letters are given. A numerical code has been given to each letter. These letters have to be unscrambled into a meaningful word. Find out the code for the word so formed from the 4 answers given.

(a) 2 3 4 1 5 6
(b) 5 6 3 4 2 1
(c) 6 1 3 5 2 4
(d) 4 2 1 3 5 6
Answer:
(b) 5 6 3 4 2 1
hint:
Given code is

Option (a) is 234156. When we substitute number for each letter from code, we get,

Option (b) is 563421, similarly, we get 5 6 3 4 2 1

Option (c) is

Option (d) is

So, only in option b, we get a meaningful word, i.e PENCIL.
Hence, answer is Option (b)

Question (iii)
In questions I and II, there are based on code language. Find the correct answer from the four alternatives given. A
C In a certain code, ‘M E D I C I N E’ is coded as ‘COMPUTER’ written in the same code?
(a) C N P R V U F Q
(b) C M N Q T U D R
(c) R F U V Q N P C
(d) R N V F T U D Q
Answer:
(C) R F U V Q N P C
Hint:
It is given that in a certain code M E D I C I N E is coded as E O J D J E F M When we observe the word & the code, we find that, there is a pattern.

[to understand, see the matching shapes]
To get the code from the word, we follow the below steps
1.
swap 1st & last letters, so we get
E [ E D I C I N ] M
2. For the middle letters, replace the letters with their alphabetically next letters, so we get

3. Now we have to reverse the order of the middle letters in the bracket, so we get
E[O J D J E F]M = E O J D J E F M
Thus we get the code.
So similarly, we have to follow the 3 steps to get code, therefore:
for

Step 1: Swap 1 st & last letters, so we get
R [O M P U T E ]C
Step 2: For the middle letters, replace the letters with alphabetically next letters, so we get
R [P N Q V U F] C
Step 3: Reverse the word of letters in the bracket to we get
R [F U V Q N P] C
∴ Ans is R F U V Q N P C ⇒ Option C

Question (iv)
If the word ‘PHONE’ is coded as ‘S K R Q H’, how will ‘R A D I O’ be coded?
(a) S C G N H
(b) V R G N G
(c) U D G L R
(d) S D H K Q
Answer:
(C) U D G L R
hint:
If PHONE is coded as S K R Q H
Find that code for R A D I O

We find that we get the code, by 3rd letter alphabetically so, from P, skipping Q & R, we get S.
Similarly, from H, skipping I & J, we get K
Like wise for R A D I O, skipping the 2 alphabets
From R, skip S & T → U
From A, skip B & C → D

From D skip E & F → G
From I skip J & K → L
From O skip P & Q → R
Answer:
is U D G L R ⇒ Option c

Question 2.
Fill in the blanks (Use Atbash Cipher that is given in code 3)
For this question, we need to use Atbash cipher. For Atbash cipher, first we write the alphabets from A to Z and then in reverse from Z to A below that.
ABCDEFGHIJKLMNOPQRSTUVWXYZ
ZYXWVUTSRQPONMLKJIHGFEDCBA

Question (i)
G Z N R O = …………
Answer:
TAMIL
Hint:
Now to solve, we look up the corresponding letter from the table to replace in code to get the actual word.
So, for G Z N R O, from table,
for G, it is T
for Z, It is A
for N, it is M
for R, it is I
for O, it is L
So , the actual word is TAMIL

Question (ii)
V M T O R H S = ………
Answer:
ENGLISH
Hint:
V M T O R H S
To solve, we look up the corresponding letter from table to replace in code to get the actual word.
For V, it is E
for M, it is N
for T, it is G
for O, it is L
for R, it is I
for H, it is S
for S, it is H
Therefore we get E N G L I S H = ENGLISH

Question (iii)
N Z G S V N Z G R X H = ………
Answer:
MATHEMATICS
Hint:
Similarly as above for

Question (v)
H X R V M X V = ………..
Answer:
SCIENCE
Hint:

Question (v)
HLXRZO HXRVMX V = ………..
Answer:
SOCIAL SCIENCE
Hint:

Question 3.
Match the following (a = 00 ……… Z = 25)

Answer:
(i) – c
(ii) – d
(iii) – a
(iv) – e
(v) – b
Solution:
Given that the code is

Hint:
(i) Mathematics is

So matching option is c

(ii) addition is

Matching option is d

(iii) Subtraction is

Matching option is a

(iv) multiplication is

Matching option is e, however instead of 25, it should be 08.

(v) division is

Matching option is b

Question 4.
Frame Additive cipher table (key = 4).
Solution:
Step 1 : write all alphabets
Step 2 : Assign numbers to each alphabet starting from 00 till 25.
Step 3 : add key value (here it is 4) to the numbers assigned in step 2 to form cipher table

Question 5.
A message like “Good Morning” written in reverse would instead be “Doog Gninrom”. In the same way decode the sentence given below: “Ot dnatsrednu taht scitamehtam nac eb decneirepxe erehwreve ni erutan dna laer efil.”
Solution:
Given that good morning written in reverse is doog gninrom.
We have to decode the below by reversing, so,
Ot dnatsrednu taht scitamehtam nac eb decneirepxe erehwreve ni erutan dna laer efil.
Answer:
to understand that mathematics can be experienced everywhere in nature and real life.

Question 6.
Decode the given Pigpen Cipher text and compare your answer to get the Activity 3 result.

(i) The room number in which the treasure took place

(ii) Place of the treasure

(iii) The name of the treasure

Solution:
(i) The room in which the treasure took place = 28
(ii) The place of treasure = Chair
(iii) Identity of treasure = Gift voucher.

Students can Download Maths Chapter 4 Information Processing Additional Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Additional Questions

Question 1.
Find HCF of 52 and 78 using repeated division.
Solution:

26 is the HCF of 52 & 78

Question 2.
Find HCF of 56 & 98 using repeated subtraction method.
Solution:
Let m = 98, n = 56
m – n = 98 – 56 = 42 ; now m = 56 & n = 42
m – n = 56 – 42 = 14 ; now m = 42 & n = 14
m – n = 42 – 14 = 28 ; now m = 14 & n = 28
m – n = 28 – 14 = 14 ; now = 14 & n = 14
∴ HCF of 98 & 56 is 14.

Question 3.
Find the first 10 terms of the Fibonacci series.
Solution:
Let us first write down the first 2 terms which are 1, 1. To find the remaining terms, we use the general formula. F(n) = F(n – 1) + F(n – 2)
∴ F(3) = F(2) + F(1)
F(1) = 1; F(2) = 1
F(3) = 1 + 1=2
F(4) = F(3) + F(2) = 2 + 1 = 3
F(5) = F(4) + F(3) = 2 + 3 = 5
∴ The first 10 terms are; 1, 1, 2, 3, 5, 8,13, 21, 34, 55

Question 4.
In a particular method of decoding, the word SECRET is written as TFDSFU. What is the cipher text for PASSWORD?
Solution:
Given that SECRET is written as TFDSFU. We notice that every letter is substituted by the next letter alphabetically.
So S is substituted by T
E by F, C by D, R by S E by F, & T by U
∴ for

similarly we have to substitute
∴ The cypher is QBTTXPSE.

Question 5.
Using the Pigpen code, decode the below message

Solution:
The pigpen code is generated by

By taking the outlines corresponding to each letter, we get

∴ The message is THANK YOU

Question 6.
Using the reflection table given below, find the encoded message Reflection table.

Message: PBATENGHYNGVBAF
Solution:
To decode the above message, let us substitute the letters that correspond’to the message from the reflection table. So, we get
P → C
B → O
A → N
T → G
E → R
N → A
G → T
H → U
Y → L
N → A
G → T
V → l
B → O
A → N
F → S
The word is CONGRATULATIONS!

Students can Download Maths Chapter 4 Information Processing Intext Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Intext Questions

Exercise 4.1
Activity 1. (Text book Page no. 83)

Question 1.
Draw a Golden Spiral using Fibonacci squares.

Answer:

Activity – 2 (Text book Page no. 85)

Question 1.
Using the given Table I, find the pattern, Answer the following questions and colour the values in the given Table II. One is done for you.
Table I

1. Where are the even Fibonacci Numbers?
Colour both the term n and where F(n) is even in
Do you find any pattern?
Every Third Fibonacci number is a multiple of 2(even).
i.e. a multiple of F(3) or 2 = F(3).

2. Where there are Fibonacci numbers which are multiple of 3?
Colour both the term n and where F(n) is multiple of 3 in red.
Write down the pattern you find
Every 4th Fibonacci number is a multiple of 3.
i.e. a multiple of F(4) or 3 = F(4).

3. What about the multiple of 5?
Colour both the term n and where F(n) is multiple of 5 in 1
Write down the pattern you find.
Every 5th Fibonacci number is a multiple of F(5) or 5 = F(5)
i.e. a multiple of F(4) or 3 = F(4)

4. What about the multiple of 8?
Colour both the term n where F(n) is multiple of 8 in green.
Write down the pattern you find.
Every 6th Fibonacci number i.e. a multiple of F(6) or 8 = F(6)

Table II

Solution:

R – Red
Y – Yellow
B – Blue
G – Green

Exercise 4.3
Try This (Text book Page no. 94)

Question 1.
Convert cipher code written in the school panel board as given in figure below.

Solution:
Cipher code given.
EAPLKEAPUSG UG NWP AJWYP NYEJKXG KOYAPUWNG, SWEFYPAPUWNG WX AVCWXUPLEG; UP UG AJWYP YNBKXGPANBUNC – QUVVAE FAYV PLYXGPWN
Mathematics is not about numbers, equations, computations or algorithms, it is about understanding. – William Paul Thurston

Activity 3. (Text book Page No. 95)

Code 1: Pigpen

Question 1.
Fill in the blank boxes and decode

The Pigpen code looks like meaningless writing, but it is quite easy to catch on to. Each letter is represented by the part of the “Pigpen” that surrounds it.

The first code uses the following key. To complete the code, you need to work out how to use the key to decode the message.

Solution:

To decode

Try These (Text book Page no. 97)

Question 1.
Use Pigpen Cipher code and write the code for your name ………. chapter names

(i) LIFE MATHEMATICS
(ii) ALGEBRA
(iii) GEOMETRY
(iv) INFORMATION PROCESSING

Solution:
For Pigpen, we should first construct the Criss Cross pattern & then fill with alphabets.
Step 1:

Step 2:
Fill the above with all the alphabets from A to Z.

Step 3:
So, the secret code is got by the outline of each letter in the above patterns. So for

Similarly for all the others. Therefore Pigpen code is

Hence if your name is RAM, the corresponding pattern is

Let us now write the given words with Pigpen code.

Question 2.
Decode the following Shifting and Substituting secret codes given below. Which one is a easier for you?

Solution:
Decode using shifting method. Let us shift & see by trial & error method.
Let us substitute ‘b’ for ‘a’, V for ‘b’ & so on.

Message: M N S G H M F H R H L O N R R H A K D
Decoded text: NOTHING IS IMPOSSIBLE
Decode using substituting method:

We find that Pigpen code has been used, by substituting for the symbols from the table that we constructed earlier, we go the message.
NOTHING IS IMPOSSIBLE

Students can Download Maths Chapter 4 Information Processing Ex 4.1 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 4 Information Processing Ex 4.1

Question 1.
Choose the correct answer:

Question (i)
What is the eleventh Fibonacci number?
(a) 55
(b) 77
(c) 89
(d) 144
Answer:
(c) 89
Hint:

∴ 11th Fibonacci number is 89

Question (ii)
If F(n) is a Fibonacci number and n = 8, which of the following is true?
(a) F(8) = F(9) + F(10)
(b) F(8) = F(7) + F(6)
(c) F(8) = F(10) x F(9)
(d) F(8) = F(7) – F(6)
Answer:
(b) F(8) = F(7) + F(6)
Hint:
Given F(n) is a Fibonacci number & n = 8
F(8) = F(7) + F (6) as any term in Fibonacci series is the sum of preceding 2 terms

Question (iii)
Every 3^rd number of the Fibonacci sequence is a multiple of ………..
(a) 2
(b) 3
(c) 5
(d) 8
Answer:
(a) 2
Hint:
Every 3rd number in Fibonacci sequence is a multiple,of 2

Question (iv)
Every ……….. number of the Fibonacci sequence is a multiple of 8
(a) 2^nd
(b) 4^th
(c) 6^th
(d) 8^th
Answer:
(c) 6^th

Question (v)
The difference between the 18th and 17th Fibonacci number is
(a) 233
(b) 377
(c) 610
(d) 987
Answer:
(d) 987
Hint:
F(18) = F(17) + F (16)
F(18) – F(17) = F(16) = F(15) + F(14) = 610-377 = 987

Question 2.
In the given graph sheet draw and colour how the Fibonacci number pattern makes a spiral in the Golden Rectangle.

Steps:
As per the instruction given, draw squares of side equal to each term of Fibonacci number – starting with 1 x 1 square, 2 x 2 square, 3 x 3 square and so on.
For spiral:
Starting from 1st square, join opposite diagonal points in a curve in all the squares to form a spiral.

Students can Download Maths Chapter 3 Geometry Ex 3.4 Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 3 Geometry Ex 3.4

Question I.
Construct the following parallelograms with the given measurements and find their area.

Question 1.
ARTS, AR = 6 cm, RT = 5 cm and ∠ART = 70°.
Solution:

Given:
In the Parallelogram ARTS,
AR = 6 cm
RT = 5 cm and ∠ART = 70°

Construction:
Steps:

1. Draw a line segment AR = 6 cm.
2. Make an angle ∠ART = 70° at R on AR
3. With R as centre, draw an arc of radius 5 cm cutting RX at T
4. Draw a line TY parallel to AR through T.
5. With T as centre, draw an arc of radius 6 cm cutting TY at S. Join AS
6. ARTS is the required parallelogram.

Calculation of area:
Area of the parallelogram ARTS = b x h sq. units
= 6 x 4.7 = 28.2 sq. cm

Question 2.
BANK, BA = 7 cm, BK = 5.6 cm and ∠KBA = 85°.
Solution:

Given:
In the parallelogram BANK, BA =7 cm, BK = 5.6 cm, and ∠KBA = 85°

Construction:
Steps:

1. Draw a line segment KB = 5.6 cm.
2. Make an angle ∠KBA = 85° at B
3. Draw an arc of radius 7 cm with B as centre on BX.
4. Draw a line AY parallel to KB.
5. With A as centre, draw an arc of radius 5.6 cm cutting AY at N. Join KN
6. BANK is the required parallelogram.

Calculation of area:
Area of the Parallelogram BANK = b x h sq. units
= 5.6 x 7 = 39.2 sq. cm

Question 3.
CAMP, CA = 6 cm, AP = 8 cm and CP = 5.5 cm.
Solution:

Given:
In the parallelogram CAMP,
CA = 6 cm
AP = 8 cm, and CP = 5.5cm

Construction:
Steps:

1. Draw a line segment CA = 6 cm.
2. With C as centre, draw an arc of length 5.5 cm
3. With A as centre, draw an arc of length 8 cm
4. Mark the intersecting point of these two arcs as P
5. Draw a line PX parallel to CA
6. With P as centre draw an arc of radius 6 cm cutting PX at M. Join AM
7. CAMP is the required parallelogram.

Calculation of area:
Area of the Parallelogram CAMP = b x h sq. units
= 6 x 5.5 = 33 sq. cm

Question 4.
DRUM, DR = 7 cm, RU = 5.5 cm and DU = 8 cm.
Solution:

Given:
In the parallelogram DRUM,
DR = 7 cm,
RU = 5.5 cm, and DU = 8 cm

Construction:
Steps:

1. Draw a line segment DR = 7 cm.
2. With D and R as centres, draw arcs of radii 8 cm and 5.5 cm.
3. Mark the intersecting point of these arcs as U. Join DU and RU
4. Draw a line UX parallel to DR through U.
5. With U as centre draw an arc of radius 7 cm cutting UX at M. Join DM
6. DRUM is the required parallelogram.

Calculation of area:
Area of the Parallelogram DRUM = b x h sq. units
= 7 x 5.4 = 37.8 sq. cm

Question 5.
EARN, ER = 10 cm, AN = 7 cm and ∠EOA 110° where \(\overline { ER } \) and \(\overline { AN } \) intersect at O.
Solution:

Given:
In the parallelogram EARN,
ER= 10 cm
AN = 7 cm, and ∠EOA = 110°

Construction:
Steps:

1. Draw a line segment PX. Mark a {Joint O on PX
2. Make an angle ∠EOA = 110° on PX at O
3. Draw arcs of radius 3.5 cm with O as centre on either side of PX. Cutting YZ on A and N
4. With A as centre, draw an arc of radius 10 cm, cutting PX at E. Join AE
5. Draw a line parallel to AE at N cutting PX at R. Join EN and AR
6. EARN is the required parallelogram

Calculation of area:
Area of the Parallelogram EARN = b x h sq. units
= 10 x 5.5 = 55 sq. cm

Question 6.
FAIR, FI = 8 cm, AR = 6 cm and ∠IOR = 80° where \(\overline { FI } \) and \(\overline { AR } \) intersect at O.
Solution:

Given:
In the parallelogram FAIR,
FI = 8cm
AR = 6 cm and ∠IOR = 80°, where \(\overline { FI } \) and \(\overline { AR } \) intersect at O

Construction:
Steps:

1. Draw a line segment \(\overline { FI } \) = 8 cm
2. Mark O the midpoint of \(\overline { FI } \)
3. Draw a line \(\overline { XY } \) through O which makes ∠IOX = 80°
4. With O as centre and 3 cm as radius draw two arcs on XY on either sides of \(\overline { FI } \). Let the arcs cut \(\overline { OX } \) at R and \(\overline { OY } \) at A
5. Join \(\overline { IR } \), \(\overline { FR } \), \(\overline { FA } \) and \(\overline { AI } \)
6. FAIR is the required parallelogram

Calculation of area:
Area of the Parallelogram FAIR = b x h sq. units
= 5.4 x 4.3 = 23.22 sq. cm

Question 7.
GAIN, GA = 7.5 cm, GI = 9 cm and ∠GAI – 100°
Solution:

Given:
In the parallelogram GAIN,
GA = 7.5 cm
GI = 9 cm and ∠GAI= 100°

Construction:
Steps:

1. Draw a line segment GA = 7.5 cm.
2. Make an angle GAI = 100° at A.
3. With G as centre, draw an arc of radius 9 cm cutting AX at I. Join GI.
4. Draw a line IY parallel to GA through I.
5. With I as centre, draw an arc of radius T.5 cm on IY cutting at N. Join GN
6. GAIN is the required parallelogram.

Calculation of area:
Area of Parallelogram GAIN = b x h sq.units
= 7.5 x 3.9 = 29.25 sq. cm

Question 8.
HERB, HE = 6 cm, ∠EHB = 60° and EB = 7 cm.
Solution:

Given:
In the parallelogram HERB,
HE = 6 cm, ∠EHB = 60° and
EB = 7 cm

Construction:
Steps:

1. Draw a line segment HE = 6 cm.
2. Make an angle ∠BHE = 60° at H.
3. With E as centre, draw an arc of radius 7 cm cutting HX at B.
4. Draw a line BY parallel to HE through B.
5. Draw an arc of radius 6 cm with B as centre, cutting BY at R. Join ER.
6. HERB is the required parallelogram.

Calculation of area:
Area of the Parallelogram HERB = b x h sq. units
= 6 x 6.7 = 40.2 sq. cm

Students can Download Maths Chapter 3 Geometry Intext Questions and Answers, Notes Pdf, Samacheer Kalvi 8th Maths Book Solutions Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus and score more marks in your examinations.

Tamilnadu Samacheer Kalvi 8th Maths Solutions Term 2 Chapter 3 Geometry Intext Questions

Exercise 3.1
Try This (Text book Page No. 60)

Question 1.
How will you prove ∆ ABC ~ AD AC?
Proof:
In ∆ ABC & ∆ DAC, ∠C is common and ∠BAC = ∠ADC = 90°
Therefore ∆ ABC ~ AD AC (AA similarity)

Try This (Text book Page No. 61)

Question 1.
Check whether the following are Pythagorean triplets

1. 57, 176, 185
2. 264, 265, 23
3. 8, 41, 40

Solution:
1. For Pythagorean triplet, the sum of the squares of 2 sides is equivalent to square of 3rd side (hypotenuse)
Let us check of
57² + 176² whether = 185² or not
57² = 3249
176² = 30976
185² = 34225
57² + 176² = 3249 + 30976 = 34225 = 185²
∴ 57, 176 & 185 are Pythagorean triplet.

2. 23, 264, 265
23² = 529
264² = 69696
23² + 264² = 70225
265² = 70225
∴ 23² + 264² = 265²
∴ Pythagorean triplet

3. 8, 41, 40
8² = 64
40² = 1600
8² + 40² = 1664
41² = 1681
8² + 40² ≠ 41² = 1
∴ They are not Pythagorean triplet

Activity – 1 (Text book Page No. 62)

We can construct sets of Pythagorean triplets as follows. Let m and n be any two positive integers (m > n):
(a, b, c) is a Pythagorean triple if a = m² – n², b = 2mn and c = m² + n² (Think, why?) Complete the table.

Solution:

Activity – 2 (Text book Page No. 65)

Question 1.
Find all integer-sided right angled triangles with hypotenuse 85
Solution:
(x + y)² – 2xy = 85²

Pythagorean triplets with hypotenuse 85.

Exercise 3.3
Try These (Text book Page No. 68)

Question 1.
The area of the trepezium is ……..
Answer:
\(\frac{1}{2}\) x h x (a + b) sq. units!

Question 2.
The distance between the parallel sides of a trapezium is called as ………
Answer:
its height

Question 3.
If the height and parallel sides of a trapezium are 5 cm, 7 cm and 5 cm respectively, then its area is ……..
Answer:
30 sq cm
Hint:
= \(\frac{1}{2}\) x h x (a + b) sq. units
= \(\frac{1}{2}\) x 5 x (7 + 5)
= \(\frac{1}{2}\) x 5 x 12 = 30 sq.cm

Question 4.
In an isosceles trapezium, the non-parallel sides are ……….. in length.
Answer:
Equal.

Question 5.
To construct a trapezium, ………… measurements are enough.
Answer:
Four.

Question 6.
If the area and sum of the parallel sides are 60 cm2 and 12 cm, its height is ………..
Answer:
10 cm
Hint:
Area of the trapezium = \(\frac{1}{2}\) x h (a + b)
60 = \(\frac{1}{2}\) x h x (12)
h = \(\frac{60×2}{12}\) = 10 cm

Exercise 3.4
Think (Text book Page No. 74)

Question 1.
Can a rhombus, a square or a rectangle be called as a parallelogram? Justify your answer.
Solution:
Yes, a rhombus, a square or a rectangle can be called as parallelogram as the opposite sides are equal and parallel and diagonals bisect each other in this figures.

Try These (Text book Page No. 74)

Question 1.
In a parallelogram, the opposite sides are …….. and ……….
Answer:
equal, parallel

Question 2.
If ∠A of a parallelogram ABCD is 100° then, find ∠B, ∠C and ∠D .
Answer:

∠B = 80°
∠C = 100°
∠D = 80°

Question 3.
Diagonals of a parallelogram each other.
Answer:
Bisect

Question 4.
If the base and height of the parallelogram are 20 cm and 5 cm then, its area is ………
Answer:
100 sq.cm

Question 5.
Find the unknown values in the given parallelograms and write the property Used to find them.

Solution: