Answer: well the diameter would be 20ft. If you meant to ask for the circumference then its 62.857ft
Explanation:
Diameter of a circle is 20 feet.
Hence it's Radius = 20/2 = 10 ft
We know circumference = 2πr
Circumference = 2 × 22/7 × 10 ft
Circumference = 44 × 10/7= 440/7
Circumference = 62.857 ft