Circles and PiCylinder Prism

Volume of a Cylinder

The top and bottom of a cylinder are two congruent circles, called bases. The height h of a cylinder is the perpendicular distance between these bases, and the radius r of a cylinder is simply the radius of the circular bases.

We can approximate a cylinder using a ${n}-sided prism. As the number of sides increases, the prism starts to look more and more like a cylinder: