Question

The area of a circle is 38.5 $c{m}^2$. The circumference of the circle is

(a) 6.2 cm (b) 12.1 cm (c) 11 cm (d) 22 cm

Answer 1

Area of circle = 38.5 sq cm That is

$\pi r^2=38.5r^2=38.5\times \frac{7}{22}=12.25$

$\therefore r=3.5cm$

Circumference of circle = 2$\pi \times r=2\times \frac{22}{7}\times 3.5=22cm$