Page 279 - Start Up Mathematics_8 (Non CCE)

EXERCISE 17.3
M
1. Find the area of the quadrilateral MARK.

K A 14 cm
13 cm

R

2. Find the area of the pentagon CHINA, if CN = 12 cm, I
CJ = 10 cm, CB = 8 cm, CG = 7 cm, HG = 7 cm, H
IJ = 9 cm and AB = 5 cm.
7 cm 9 cm

7 cm B
C N
G J
5 cm

A
3. Find the area enclosed by the following figures:
Q U K R
22 cm
S 4 cm 4 cm
8 cm 16 cm 4 cm 4 cm
S T
E
5 cm 5 cm
A
R 30 cm P 6 cm A
(a) (b)

4. A pentagon is divided in two different ways by Aditya and Noni as shown in the figure. Find the area
of this pentagon using both ways.

36 cm
18 cm
18 cm

18 cm Aditya’s diagram Noni’s diagram

AT a Glance

1
1. Area of a trapezium = × (Sum of lengths of parallel sides) × Height
2
2. A polygon is a closed figure consisting of three or more line segments (sides) such that each line intersects
exactly two others at its end point (vertices) and no two line segments which intersect are collinear.
3. To find the area of a regular or irregular polygon, we divide it into triangles, trapeziums, parallelograms,
etc. and find the area of each figure. The area of the polygon is equal to the sum of these areas.

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