Answer
The distance around the crater is approximately 12560 feet
Work Step by Step
The distance around the crater is the circumference of the crater
Circumference = $\pi$ $\times$ diameter = $\pi$ $\times$ d
Circumference = $\pi$ $\times$ 4000 = 4000$\pi$ feet
The approximation of the circumference = 4000 $\times$ 3.14 = 12560 feet