Arc Length
GCSE Version to A-Level Version
- In GCSE we used the equation \(l=\frac{\theta}{360}\times2\pi r\)
- Now we are using radians, so this becomes \(l=\frac{\theta}{2\pi}\times2\pi r\)
- The \(2\pi\) can cancel and we are left with \(l=\theta r\), where \(\theta\) is measured in radians.