# Curved Surface Area of Right Circular Cylinder

## Definition of Curved Surface Area of Right Circular Cylinder

The Curved Surface Area of Right Circular Cylinder may be defined as the surface area of the cylinder excluding the area of the top and the bottom faces.

## Explanation

To understand the concept of the Curved Surface Area of Right Circular Cylinder, let us consider a hollow Right Circular Cylinder as shown in the figure below. Now if the top and the bottom faces of the Right Circular Cylinder is removed than we will get a shape similar to the right-hand side of the figure.

The surface area for the above shape that does not include the surface area of the top of the bottom faces is called the Curved Surface Area of the Right Circular Cylinder.

## Curved Surface Area of Right Circular Cylinder Formula

If the Right Circular Cylinder is cut along the line that is parallel to the edge as shown in the figure below, then a rectangular shape is obtained.

Therefore, the Curved Surface Area of Right Circular Cylinder is equal to the area of the Triangle and is given by,

Curved Surface Area $=l\times h$

Where, $l$ is the length and $h$ is the height of the Right Circular Cylinder. From the figure it is clear that the length $l$ is equal to the circumference or perimeter of the circular faces. If, $r$ is the radius of the circular base then the value of $l$ can be found out by,

$l=2\pi r$

Therefore, the above formula for finding the Curved Surface Area of Right Circular Cylinder can be modified as,

Curved Surface Area $=2\pi r h$