# Circumference of a Circle

The circumference of the circle is the total distance around a closed curve. In other words, the circumference is the total length around the circle. It is measured in linear units, like centimeters or inches.

## Circumference of a Circle Formula

The formula of circumference of a circle is given by the following formula,

Circumference, $C = 2 * \pi * r$

where, r is the radius of the circle.

and pi is a constant value and is equal to 3.14

The circumference of a circle can be calculated by its diameter using the following formula:

Circumference, $C = \pi * D$

Where, value of $\pi$ is a constant and its value is approximately 3.14159265358979323846.... or 22/7 to be more precise and D is the diameter of the circle. To simplify calculations the value of $\pi$ is rounded to 3.14. The diameter of a circle is twice its radius. Therefore, Circumference, $C = 2 \pi r$ ## Circumference of a Circle Examples

Below are the examples on circumference of a circle -

## Example 1:

Find the circumference of a circle given that its radius is 8.

## Solution:

The circumference is always multiply by 2 the length of the radius,

## Formula

Circumference of circle = $2 \pi r$

Circumference = $2 * 8 * \pi = 50.24$

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