Question

In the given figure, OABC is a quadrant of a circle of radius 3.5 cm with centre O. If OD = 2 cm, find the area of the shaded portion.

Answer 1

Area of the right-angled `Delta COD = 1/2xx"b"xx"h"`

`=1/2xx3.5xx2 = 3.5  "cm"^2`

Area of the sector  AOC`=theta/360xxpixx"r"^2`

`=90/360xx22/7xx(3.5)^2`

= 9.625 cm²  

Area of the shaded region = Area of the ΔCOD - Area of the sector AOC

= 9.625 - 3.50

= 6.125 cm²