Answer:
circumference = 20π miles (or ≈ 62.83 miles)
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