Find the area of a circle whose circum­ference is 44 cm.

Given:

Circum­ference of a circle is $44\ cm$.

To do:

We have to find the area of the circle.

Solution:

Let the radius of the circle be $r$.

We know that,

Circumference of a circle of radius $r=2 \pi r$

Area of a circle of radius $r=\pi r^2$

Therefore,

Circumference of the given circle $=2 \times \frac{22}{7} \times r$

$44=\frac{44}{7} \times r \mathrm{~cm}$

$r=7 \mathrm{~cm}$.

Area of the given circle $=\frac{22}{7} \times(7)^{2} \mathrm{cm}^{2}$

$=22 \times 7 \mathrm{~cm}^{2}$

$=154 \mathrm{~cm}^{2}$

The area of the circle is $154\ cm^2$.