Question

the radius of a circle is 20 cm. find its circumference in terms of $pi$.

Explanation:

Step1: Recall circumference formula

The formula for the circumference of a circle is $C = 2\pi r$, where $r$ is the radius.

Step2: Substitute radius value

Substitute $r = 20$ cm into the formula:
$C = 2\pi \times 20$

Step3: Calculate the product

Simplify the expression:
$C = 40\pi$

Answer:

$40\pi$ cm