Question

The radius of circle is $9$cm. Find the length of an arc of this circle which cuts off a chord of length equal to the radius.

Answer 1

$\begin{array}{c}\sin \theta =\frac{4.5}{9}=\frac{1}{2}\\ \theta ={30}^{\circ }\\ \angle AOB={60}^{\circ }\\ LengthofArc=\theta .R\\ =60\times 9\\ =\frac{\pi }{3}\times 9\\ =3\pi \end{array}$