Geometry Problem

Question

How to calcualte the surface area of a cone with 6 cm radious and 15 cm height

Answer 1

If you have the slant height, it's a little easier (that equation is SA = πr² + πr(s) where "s" is the slant height). Since you don't have the slant height, you have to calculate it using the Pythagorean Theorem s = √(h² + r²)

So SA = πr² + πr√(h² + r²) = π(6)² + π(6)√(15² + 6²) = 36π + 6π√261 = 36π + 6π(3√29) = 36π + 18π√29 = 18π(2 + √29) sq cm ≈ 417.62 sq cm