MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER First give the exact answer, expressed as a simplified radical expression. Then give an approximation, rounded to the nearest tenth, The surface area of a cone is given by the formula S =wry / + h2, where ; is the radius of the base and h is its height, Use this formula to find the number of square feet of waterproof cloth used to make the umbrella. (Assume h = 4 and r = 8.) exact answer S = 8nV 80 2 x X approximation 5 = 225 it 2 r it