The surface area of a cylinder — lesson. Mathematics CBSE, Class 8.

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A cylinder has two plane ends. Each plane end is circular, and these two plane ends are parallel to each other.

Also, a cylinder has two dimensions, namely radius and height.

The net of a cylinder looks like this.

$\text{The total surface area of a cylinder}$

$=$

$\text{Area}$

$1$

$+$

$\text{Area}$

$2$

$+$

$\text{Area}$

$3$

$= \pi r^2 + 2\pi rh + \pi r^2$

[Since

$\text{Area}$

$1$ and

$\text{Area}$

$3$ are circles]

$= 2\pi r^2 + 2\pi rh$

$= 2\pi r(r + h)$

Let us now look at the lateral surface of the cylinder.

The shaded portion forms the lateral surface of the cylinder.

$\text{The lateral (or curved) surface area of a cylinder}$

$=$

$\text{Area}$

$2$

$=$

$2\pi rh$

Did you find an error?

2. The surface area of a cylinder