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  length of the boundary of the shaded region.

 

Answer 1

Now we will find length of the boundary of the shaded region.

`∴ "Length of the boundary the shaded region"=2pi r+AB+DC`

`∴ "Length of the boundary the shaded region"=2xx22/7xx7+20+20`

`∴ "Length of the boundary the shaded region"=2xx22+40`

`∴ "Length of the boundary the shaded region"=44+40`

`∴ "Length of the boundary the shaded region"=84`

Therefore, length of the boundary of the shaded region is `84 cm`