How do you do the surface area for a cylinder?

Answer 1

Let the cylinder have circular ends of radius r and height h.

There are two circular ends which each have an area of {pi}r2, and the curved side of the cylinder; if a cut was made down it from one end to the other, it could be "unrolled" into a rectangle with its length the height of the cylinder, and width the perimeter of one of the ends which is given by 2{pi}r, giving an area of 2{pi}rh..

Surface area = 2 x area_of_end + area_of_side

= 2 {pi} r2 + 2 {pi} r h

= 2 {pi} r (r + h)