Chapter 12.6, Problem 3CYU

To determine

Calculate the lateral and surface area of cylinder having diameter of 4.2 m and height of 7.8m

Answer to Problem 3CYU

Lateral area of cylinder= $102.91m^2$

Surface area of cylinder= $130.61m^2$

Explanation of Solution

Given:

Diameter=4.2m; Radius= 2.1 yd

Height =7.8m

Calculations:

Here, we have to calculate lateral and surface area of cylinder.

We know that, surface area of cylinder is calculated as,

  $Surfacearea=2\pi r^2+2\pi rh$

Where, $r$ is the radius of cylinder h is the height of cylinder

Putting values in equation, we get

  $\begin{array}{l}Surfacearea=2\pi r^2+2\pi rh\\ =(2\times \pi \times {2.1}^2)+(2\times \pi \times 2.1\times 7.8)\\ =27.70+102.91\\ =130.61m^2\end{array}$

We know that, lateral surface area of cylinder is calculated as,

  $\begin{array}{l}LateralSurfacearea=2\pi rh\\ =(2\times \pi \times 2.1\times 7.8)\\ =102.91m^2\end{array}$

Conclusion:

Therefore, we are able to calculate lateral and surface area of cylinder.