 # Smartick - Math, one click away

Try it for free Nov14

## What Are Cylinders?

In this week’s post, we will look at cylinders. Have you heard of them? Do you know what they are? Do you know their characteristics? We will talk about all of this below.

##### What are cylinders?

Cylinders are geometric solids that are formed by a rectangle rotating about one of its sides.

##### A cylinder is formed by a rectangle, which is the side of the cylinder and two circles, which are the two bases of the cylinder. What are the parts of the cylinder?
• The axis is the side of the rectangle that remains fixed in rotation.
• the bases are the two circles, perpendicular to the axis.
• The height is the distance between the two bases.
• The radius (r) is the length from the axis to the side of the cylinder. It corresponds to the radius of the base. ##### How is the area of a cylinder calculated?

You first have to find the area of each part of the cylinder and then add them.

Area of the rectangle = 2πrh

Area of the base = πr2
Adding all parts of the cylinder, we get the area = 2πrh + 2πr2

Area = 2πr(h + r)

##### How is the volume of the cylinder calculated?

The volume is equal to the area of the base multiplied by the height:

Volume = πr2h