Question

i need to practice on finding the surface area of a cylinder

Answer 1

We know that a cylinder is defined by two measurements. The radius and the height.

The surface area of a cylinder is given by:

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

Example.

Imagine you have a cylinder that has a radius of 10 cm and a height of 25 cm. Then plugging the values into the equation above we have:

$\begin{gathered} A=2\pi(10)^2+2\pi(10)(25) \\ A=2\pi(100)+500\pi \\ A=200\pi+500\pi\text{ } \\ A=700\pi \end{gathered}$

Therefore the surface area is 700pi squared cm. If we use 3.14 for pi we have that the surface area is 2198 squared cm.