Answer:
100π square inches
Explanation:
The area of a circle is given by ...
A = πr^2
where r is the radius. The radius of a circle is half the diameter, so your circle with 20 inch diameter has a radius of 10 inches. Putting that value into the formula gives an area of ...
A = π·(10 in)^2 = 100π in^2
The area is 100π square inches.