Diagram of the adjacent picture frame has outer dimensions = 24 c m × 28 c m and inner dimensions 16 c m × 20 c m . Find the area of each section of the frame, if the width of each section is same.

Given that width of each section is same. ∴ I B = B J = C K = C L = D M = D N = A O = A P And I L = I B + B C + C L ⇒ 28 = I B + 20 + C L ⇒ I B + C L = 28 c m - 20 c m = 8 c m ⇒ I B = C L = 4 c m Hence, I B = B J = C K = C L = D M = D N = A O = A P = 4 c m Area of section B E F C = Area of section ADGH Area of section ABEH = Area of section CDGF We know that, A r e a o f T r a p e z i u m = 1 2 × s u m o f p a r a l l e l s i d e s × p e r p e n d i c u l a r d i s t a n c e . Area of section B E F C = Area of section ADGH = 1 2 20 + 28 4 cm 2 = 96 cm 2 Area of section A B E H = Area of section CDGF = 1 2 16 + 24 4 = 80 c m 2 Hence, area of each section 80 cm 2 , 80 cm 2 , 96 cm 2 , 96 cm 2 respectively.

E M B I B E

MATHEMATICS Textbook for Class VIII>Chapter 11 - Mensuration>EXERCISE>Q 6

MEDIUM

8th Mizoram Board

IMPORTANT

Earn 100

Find the area of a rhombus whose side is $5 c m$ and whose altitude is $4.8 c m .$ If one of its diagonals is $8 cm$ long, find the length of the other diagonal.

Important Questions on Mensuration

MEDIUM

8th Mizoram Board

IMPORTANT

MATHEMATICS Textbook for Class VIII>Chapter 11 - Mensuration>EXERCISE>Q 7

The floor of a building consists of

3000

tiles which are rhombus shaped and each of its diagonals are

45 c m

and

30 c m

in length. If the total cost of polishing the floor is

₹ k

when the cost per

m^{2}

is

₹ 4

, then find the value of

k

.

HARD

8th Mizoram Board

IMPORTANT

MATHEMATICS Textbook for Class VIII>Chapter 11 - Mensuration>EXERCISE>Q 8

Mohan wants to buy a trapezium shaped field. Its side along the river is parallel to and twice the side along the road. If the area of this field is

10500 m^{2}

, the perpendicular distance between the two parallel sides is

100 m

and the length of the side along the river is

k m

, then find the value of

k

.

HARD

8th Mizoram Board

IMPORTANT

MATHEMATICS Textbook for Class VIII>Chapter 11 - Mensuration>EXERCISE>Q 9

Top surface of a raised platform is in the shape of a regular octagon as shown in the figure. If the area of the octagonal surface is $k m^{2}$ , find $k$ .

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HARD

8th Mizoram Board

IMPORTANT

MATHEMATICS Textbook for Class VIII>Chapter 11 - Mensuration>EXERCISE>Q 10

There is a pentagonal-shaped park as shown in the figure. For finding its area Jyoti and Kavita divided it in two different ways. Find the area of this park using both ways.
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