The circumference of a circle is 39.6 cm. Find its area.

Circumference = 39.6 cm
We know:

Circumference of a circle $=2 \pi r$

$\Rightarrow 39.6=2 \times \frac{22}{7} \times r$

$\Rightarrow \frac{39.6 \times 7}{2 \times 22}=r$

$\Rightarrow r=6.3 \mathrm{~cm}$

Also,

Area of the circle $=\pi r^{2}$

$=\frac{22}{7} \times 6.3 \times 6.3$

$=124.74 \mathrm{~cm}^{2}$