Question

What is the radius of this circle if the circumference is 18π cm? 3 cm 9 cm 18 cm 36 cm

Answer 1

Answer:

The radius is 9 cm.

Step-by-step explanation:

The formula for calculating the circumference of a circle is

$C=2\pi r$

Where r is the radius and C is the circumference.

It was given in the question that; the circumference, $C=18\pi cm$.

We substitute this into the formula to obtain;

$18\pi=2\pi r$

Divide both sides by $2\pi$

$\frac{18\pi}{2\pi}=r$

$9=r$

The radius is 9cm