Find the area of a circle with a radius of 21 inches.
The formula for the area of a circle is A = πr^2, where r is the radius.
Plugging in r = 21 inches, we get:
A = π(21)^2
A = π441
A = 1385.44
Therefore, the area of the circle with a radius of 21 inches is approximately 1385.44 square inches.