Volume and surface area of cylinders

A cylinder is a circular prism. In other words it has a circular cross section.

This makes finding the volume straight forward. All you need to do is calculate the area of the circle on the end (using Area = pi x radius squared) and multiply it by the length.

To find the surface area you must imagine the net of a cylinder (this is when it is folded out flat). The net consists of two circles (the ends) and the curved surface which is a rectangle.

The length of the rectangle is equal to the circumference of the circular cross section and so can be found using Circumference = pi x diameter.