A circle that is 18 feet wide what is the square footage?

Assuming you mean 18 ft in diameter. The formula to find the Area of a circle is: A = Pi x R² where Pi is 3.1416 and R² is the radius multiplied by itself. The Radius is one-half the diameter. Using the formula and substituing the values: A = 3.1416 x (9 x 9) = 3.1416 x 81 = 254.4696 sq ft.