The diameter of a circle is 20 miles. What is the circumference?

The circumference of the circle having 20 ft diameter is 62.857 ft.

circumference = 20π miles (or ≈ 62.83 miles)

Step-by-step explanation:

The formula for the circumference of a circle is:

circumference = 2πr OR circumference = dπ

Since you are given the diameter, input that into the formula and the answer will be:

circumference = 20π

If you need to get rid of the π, the answer is about 62.83