# Arc Length of a Circle

A sector is a fraction of the area of a circle.

### arc Length of a formula

\(\large{ l = \theta \; r \;\; }\) (when \(\; \theta \;\) is in radians)

\(\large{ l = \theta \; \frac { \pi } { 180 } \; r \;\; }\) (when \(\; \theta \;\) is in degrees)

Where:

\(\large{ l }\) = length

\(\large{ \pi }i\) = Pi

\(\large{ r }\) = radius

\(\large{ \theta }\) = angle