Question

. A circular lawn of diameter 30
m contains a small rectangu-
lar lake 15m x 10 m. The re-
maining portion contains
grass. The area of the grass is
nearly
​

Answer 1

Circumference of a circle = 2 × pi × r = d × pi

d × pi = 30

d = 30/pi

Diameter of lawn = 30/pi

Radius of lawn = 30/2pi = 15/pi

Area of a circle = pi × r × r

Area of lawn = pi × (15/pi)^2 = 225/pi

Area of a rectangle = l × b

Area of lake = 15 × 10 = 150 m

Area of grass = area of lawn - area of lake = 225/pi - 150 = 75/pi = 75×7/22 = 525/22 = 22.86 m approximately.

:-)