# Arc Length of a Circle

Written by Jerry Ratzlaff on . Posted in Plane Geometry

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