Question

ABCD is a rectangle of length 20 cm and breadth 10 cm. OAPB is a sector
of a circle of radius 10√2 cm. Calculate the area of the shaded region
| Take n = 3:14]
D
20 cm
C
P
10 cm
20
93
B
А
1072 cm
Area of
o​

Answer 1

Given:

ABCD is a rectangle of length 20 cm and breadth 10 cm. OAPB is a sector of a circle of radius 10√2 cm.

To find:

Calculate the area of the shaded region. | Take n = 3:14]

Solution:

Area of APB = Area of sector OAPB - Area of Δ OAB

= θ/360° (πr²) - 1/2bh

= 90°/360° × 22/7 × (10√2)² - 1/2 × 20 × 10

= (11×100 - 7×100) / 7

= 400/7

Area of shaded region = Area of rectangle ABCD - Area of APB

= 20 × 10 - 400/7

= 1000/7 cm²