In the given figure, ABCD is a rectangle of dimensions 21 cm x 14 cm

Mensuration (10)

In the given figure, ABCD is a rectangle of dimensions 21 cm x 14 cm. A semicircle is drawn with BC as diameter. Find the area and the perimeter of the shaded region in the figure.

Answer

Area of shaded region = (21 x 14) - $ \frac{1}{2} \times π \times 7 \times 7 $

= 294 - $\frac{1}{2} \times \frac{22}{7} \times 7 \times 7$

= 294 – 77 

= 217 cm2 

Perimeter of shaded region =  21 +14 + 21 + $ \frac{22}{7} \times 7 $

= 56 + 22 

= 78 cm

Exam Year: 2017