This page will show you how to calcualte various things related to cylinders.
Notes about cylinders:
The radius R, or the distance from the center of a cylinder to its edge, and its length, L are usually the defining property of a cylinder. If your cylinder is standing upright, you might call the "length" a "height" instead.
The diameter, or the distance across a cylinder that passes through the center of the cylinder is 2R (twice the radius).
The surface area of an open ended cylinder (as shown) is 2RL
If the cylinder has caps on the ends, the surface area is 2RL+2R2