<Dl> <Dd> L = α π r 180 . (\ displaystyle L = (\ frac (\ alpha \ pi r) (180)).) </Dd> </Dl> <Dd> L = α π r 180 . (\ displaystyle L = (\ frac (\ alpha \ pi r) (180)).) </Dd> <P> A practical way to determine the length of an arc in a circle is to plot two lines from the arc's endpoints to the center of the circle, measure the angle where the two lines meet the center, then solve for L by cross-multiplying the statement: </P> <Dl> <Dd> measure of angle in degrees / 360 ° = L / circumference . </Dd> </Dl>

The two points that mark the end of an arc