Basic College Mathematics (9th Edition)

C $\approx$ 25.12 km
C = 2 $\pi$r where $\pi$is approximately 3.14, r is 4 km What is the area if $\pi$ is approximately 3.14 and r is 4 km Evaluate the formula by replacing $\pi$ with 3.14 , r with 4 km C = 2 * 3.14 * 4 km $\approx$ 25.12 km