A cylinder is a prism whose bases are curved surfaces rather than polygons.
A circular cylinder has bases which are circles, and a right circular cylinder is a right angled prism whose bases are circles. A typical soda can is a right circular cylinder. The line joining the centers of the bases is called the axis of the cylinder. Generally, when we say cylinder, a right circular cylinder is implied.
Surface Area of a Cylinder
To find the area of the curved surface of a cylinder, consider cutting the curved surface along the vertical line and ‘unrolling’ the surface.
We will form a rectangle, where one side of the rectangle is the altitude, of the cylinder, and the other is the circumference, , of the bases. To visualize this better, wrap a piece of paper around it. This should make it clear that the curved surface of a cylinder is actually a rectangle. Thus, the Lateral Surface Area of a cylinder is , and as the sum of the area of the curved surface and the two circular ends, we get
Volume of a Cylinder
Just as in the case of a cuboid, volume of a cylinder can be measured by filling it with circular sheets of paper.