Page 187 - Maths Skills - 8

Mensuration 185

6. In a cube, length, breadth and height are: 1
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(i) equal 5. Area of a trapezium = × base × height.
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(ii) sometimes equal and sometimes unequal 6. 1 m = 1000000 cm .
(iii) unequal (iv) none of these 7. Area of the four walls of a rooms is 2b (l +h)
7. Solids are ______________ figures.

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(i) two dimensional 8. Surface area of a cuboid is 4(side) .
(ii) three dimensional 9. Volume of a cube is (side) .
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(iii) four dimensional 10. The volume of a cuboid whose breadth is half
(iv) none of these of its length (x) and height is double the length
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8. 1 dm is equal to: is x .
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(i) 10 cm (ii) 100 cm 3 D. Case Study Based Questions
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(iii) 1000 cm (iv) 1000 m 3 A building was constructed by Mohan. In this
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9. The standard unit of volume is: building, 15 cylindrical pillar were constructed. Now
(i) 1 m (ii) 1 cm 3 all these pillars were to be painted. The diameter of
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each pillar was 48 cm and height was 7 cm.
(iii) 1 mm (iv) 1 dm 3 Answer the following questions on the basis of the
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10. A cuboid has _________ faces, _________ above data.
edges and _________ vertices. 1. What is the radius of each pillar in m?

(i) 8, 6, 5 (ii) 6, 7, 6 (i) 9.6 m (ii) 2.4 m
(iii) 6, 8, 12 (iv) 6, 12, 8 (iii) 0.96 m (iv) 0.24 m

B. Fill in the Blanks 2. Which area should be calculated to know the
1. Area of a square is ___________. requirement of paint?
2. The unit of area is ___________. (i) Total S.A. (ii) Curved S.A.

3. 1 cm = ___________ mm . (iii) Area of top
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4. 1 dm = ___________ m . (iv) Curved S.A. + Area of top
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5. Area is a ___________ dimensional concept. 3. What is the formula to find curved S.A. of
cylinder?
6. Volume of a cuboid = ___________. (i) πrh (ii) 2πrh
7. Volume of a cube = ___________. (iii) πr h (iv) 2πr h
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8. Sum of the areas of all the six faces of a cuboid
is called ___________. 4. Find the curved S.A. of one cylindrical pillar.
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9. 1 m = ___________ dm . (i) 8.56 m (ii) 10.56 m 2
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10. Surface area of a cylinder = ___________. (iii) 12.56 m (iv) 6.56 m 2
E. Assertion-Reason Based Questions
C. Write ‘T’ for true and ‘F’ for false statements
Directions for Questions 1 to 2: In each of the
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1. The area of a triangle = × base × altitude. questions given below, there are two statements
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marked as Assertion (A) and Reason (R). Mark your
2. 1 km = 10 m . answer as per the codes provided below:
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3. 1 dm = 100 cm . (a) Both A and R are true and R is the correct
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explanation of A.
4. Area of a square of side 7 m is 28 m .
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