# How do you find the circumference and the area of a circle with radius is 4 feet?

The circumference is $8 \pi$
The area is $16 \pi$
The formula for circumference is $2 \pi r$, so $2 \cdot \pi \cdot r$ is $2 \cdot 4 \cdot \pi$, or $8 \pi$.
The formula for area is $\pi {r}^{2}$, so $\pi \cdot r \cdot r$ is $16 \pi$.