sylinder? there you go:
SA consists of two circles(the floor, and the top) and rectangle around
Circle area: pi x r^2 (one, you need to x2, because you have 2 of them)
Rectangle area= L x H
The hight H is the hight of your cylinder, the length L is the length of the bottom circle, it's circumference, C=pi x diameter ( when you make your cylinder, you twist this rectangle around the bottom circle, so as long your circle, as long your latteral rectangle.