A cylinder has three faces: two circular bases with one rectangular lateral area between them. Because a cylinder is a curved figure, the term "sides" is not used to describe its shape.
The volume of a cylinder is determined by multiplying the area of its base by its height. This is typically done in two steps. Because the base of a cylinder is a circle, that area is found by multiplying pi by the circle's radius squared. This result is then multiplied by the height of the cylinder. The answer, given in cube units, is the cylinder's volume, which is amount of space the cylinder encloses.