Question 22

The area of a semicircle is $$308 cm^2$$ . Calculate its perimeter (in cm).

Solution

Let radius of semi circle = $$r$$ cm

Area = $$\frac{\pi r^2}{2}=308$$

=> $$\frac{22}{7}\times\frac{1}{2}\times r^2=308$$

=> $$r^2=308\times\frac{7}{11}=196$$

=> $$r=\sqrt{196}=14$$ cm

$$\therefore$$ Perimeter of semi circle = $$\pi r+2r$$

= $$(\frac{22}{7}\times14)+(2\times14)$$

= $$44+28=72$$ cm

=> Ans - (D)

Share on Whatsapp Share on Whatsapp

Create a FREE account and get: