# Cylinder

A body bounded by a cylindrical surface (cylinder) and two parallel planes intersecting it. The parts of the plane lying inside the cylindrical surface are called the bases of the cylinder, the part of the cylindrical surface between the bases is called the lateral surface of the cylinder. If the bases of the cylinder are discs, then the cylinder is called circular. If the generators of the lateral surface are perpendicular to the planes of the bases, then the cylinder is called rectangular. The axis of a rectangular circular cylinder is the line passing through the centres of the bases. The volume of a rectangular circular cylinder is $\pi R^2h$, where $R$ is the radius of the bases and $h$ the height of the cylinder; the area of the lateral surface is $2\pi Rh$.