# The radius of a circle is (7n-21) inches. How do you find the circumference of the circle in terms of n?

Jan 3, 2017

$\pi$(14n-42)

#### Explanation:

To find the circumference of a circle, you use the formula of $C = \pi \cdot \mathrm{di} a m e t e r$ or $C = 2 \pi \cdot r a \mathrm{di} u s$.

To find the diameter of the circle, you would multiply the radius by 2.
2(7n-21) = 14n-42

Now, multiply by pi: $\pi$(14n-42) or an incredibly long decimal that you can look up yourself if you want an exact answer.