If the perimeter of a semicircle is 72 cm, then find its area $$(in cm^2)$$.
Let radius of semi circle = $$r$$ cm
=> Perimeter of semi circle = $$\pi r+2r=72$$
=> $$r(\frac{22}{7}+2)=72$$
=> $$r(\frac{22+14}{7})=72$$
=> $$r=72\times\frac{7}{36}=14$$ cm
$$\therefore$$ Area of semi-circle = $$\frac{1}{2} \pi r^2$$
= $$\frac{1}{2}\times\frac{22}{7}\times(14)^2$$
= $$22\times14=308$$ $$cm^2$$
=> Ans - (A)
Create a FREE account and get:
