Question

In the following figure, ABCD is a rectangle, having AB = 20 cm and BC = 14 cm. Two sectors of 180° have been cut off. Calculate:

the area of the shaded region.

 

Answer 1

 We have given two semi-circles and a rectangle.

Area of the shaded region = Area of the rectangle − Area of the two semicircles 

`∴ "Area of the shaded region" =20xx14-2xx1/2xxpixx7xx7`  

Substituting pi=`22/7` we get,

`∴ "Area of the shaded region"=20xx14-2xx1/2xx22/7xx7xx7` 

`∴ "Area of the shaded region"=20xx14-22xx7`

`∴ "Area of the shaded region"280-154` 

`∴ "Area of the shaded region"=126`

Therefore, area of shaded region is `126 cm^2`