# How do we find an area of a circle ?!

May 2, 2018

We use the formula $\pi {r}^{2}$.

#### Explanation:

Where,

$\pi$ is a constant number. In fact, it is the ratio of the circumference to the diameter of any circle. It is approximately $3.1416$.

${r}^{2}$ is the square of the radius of the circle.

Example : The area of a circle with radius $10$ cm would be:

$= \pi \times {10}^{2}$
$= 3.1416 \times 100$
$= 314.16 c {m}^{2}$