Question

The circumference of a circle is equal to $72\pi$. Find the radius of this circle.

• A. $21$
• B. $42$
• C. $36$
• D. $8$

Answer 1

Answer: (C)

$36$

We know, circumference of a circle $=2\pi r$, where, $r$ is a radius of a circle.

Given, the circumference of the circle $=72\pi$

$\Rightarrow$ $2\pi r=72\pi$

$\Rightarrow$ $2r=72$

$\Rightarrow$ $r=\frac{72}{2}$

$\therefore$ $r=36$.

$\therefore$ Radius of the circle is $36$ unit.

Hence, option $C$ is correct.