Question

Find, in terms of the $\pi$, the length of the arc that subtends an angle of ${30}^{\circ }$ at the centre of a circle of radius 4 cm.

Answer 1

We know that the arc length $l$ of a sector of an angle $\theta$ in a circle of radius $r$ is

$l=\frac{\theta }{{360}^o}\times 2\pi r$

$=\frac{{30}^o}{{360}^o}\times 2\pi \times 4$

$=\frac{2\pi }{3}cm$