Question

In the given figure, AB and CD are diameters of a circle with centre O perpendicular to each other. If OA = 7 cm, find the area of shaded region.

Answer 1

Radius of circle (r) = OA = 7 cm.

Area of the semicircle = `1/2xxpi"r"^2`

= `1/2xx22/7xx7xx7`

= 11 × 7

= 77 cm²

Area of ΔABC = `1/2` × base × height 

= `1/2xx14xx7`

= 49 cm²

.·. Area of the shaded portion = Area of semicircle - Area of the ΔABC

= 77 - 49 

= 28 cm²