Question

In the fig. 9.14 the radius of an inscribed circle in the square is 10 cm. Find the area of shaded portion.

Answer 1

Radius of an inscribed circle, r = 10 cm
Diameter of the circle = 2 × radius = 2 × 10 cm = 20 cm
Side of the square = diameter of the circle = 20 cm
Area of the square = (side)² = (20 cm)² = 400 cm²
Area of the circle =$\pi$r²
= 3.14× (10 cm)²
= 314 cm²
∴ Area of the shaded portion = area of the square − area of the circle
= (400 – 314) cm²
= 86 cm²