The circumference of a circle is 22 cm. Find its area.

Let r cm be the radius of the circle.
Now,
Circumference of the circle:

$2 \pi r=22$

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

$\Rightarrow r=\left(22 \times \frac{7}{44}\right) \mathrm{cm}$

$\Rightarrow r=\frac{7}{2}$

Also,

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

$=\left(\frac{22}{7} \times \frac{7}{2} \times \frac{7}{2}\right) \mathrm{cm}^{2}$

$=\frac{77}{2} \mathrm{~cm}^{2}$

$=38.5 \mathrm{~cm}^{2}$