The surface area of a sphere is equal to [4 x Pi x R^2]. In other words, four multiplied by 3.14 multiplied by the radius squared. If the radius of a sphere is 15 yards, the approximate surface area is [4 x 3.14 x (15x15)] = [12.5 x 225] = [2,812 yd^2]. The surface area of a sphere with radius 15 yd is approximately 2,800 yards.