Question

find the length s of the arc of a circle of radius 75 inches subtended by the central angle 21°

Answer 1

$\bf \textit{arc's length}\\\\ s=\cfrac{\theta \pi r}{180}~~ \begin{cases} r=radius\\ \theta =angle~in\\ \qquad degrees\\[-0.5em] \hrulefill\\ r=75\\ \theta =21 \end{cases}\implies s=\cfrac{(21)(\pi )(75)}{180}\implies s=\cfrac{35\pi }{4}$