# What is the circumference of a circle with a radius of 11?

Apr 23, 2018

$68.1$

#### Explanation:

There's a special formula for the circumference of a circle, and it is:

$C = 2 \pi r$

$\text{r = radius}$

The problem tells us that $r = 11$, so just plug that into the equation and solve:

$C = 2 \pi r$

$C = 2 \pi \left(11\right)$

$C = 22 \pi$

$\pi$ is approximately $3.14$, so multiply:

$C = 22 \left(3.14\right)$

$C = 68.08 \rightarrow 68.1$

The circumference is approximately $68.1$.