The formula for the surface area of a sphere is 4πr2. What is the surface area of a ball with a diameter of 6 inches? Round to the nearest inch. (π = 3.14)
If the diameter of a sphere is 6 inches, the radius is 3 inches. The radius of a circle is half the diameter. Using the radius of 3 inches, surface area equals (4)(3.14)(3)2 or 113.04 in2. Rounding this to the nearest inch is 113 in2.