To find the surface area of a cylinder add the surface area of each end plus the surface area of the side. Each end is a circle so the surface area of each end is pi * r2, where r is the radius of the end. There are two ends so their combinded surface area is 2 pi * r2. The surface area of the side is the circumference times the height or 2 pi * r * h, where r is the radius and h is the height of the side.
The entire formula for the surface area of a cylinder is 2 pi r2 + 2 pi r h