What is Circumference?
The perimeter of a circle is called circumference.
Circumference Formulas
There are two formulas you can use to find the circumference of a circle. The first one is used the most often, but they both mean the same thing because the diameter of a circle is equivalent to two radii.
Circumference from Radius
\[C=2\pi r\]
Circumference from Diameter
\[C=\pi d\]
How to Find the Circumference of a Circle
- Identify the diameter or radius of the circle.
- Plug the number into the Circumference Formula.
