Question

Find the length s of the arc of a circle radius 40 miles subtended by the central angle 1/8 radian

Answer 1

$\bf \textit{arc's length}\\\\ s=r\theta \quad \begin{cases} r=radius\\ \theta =angle~in\\ \qquad radians\\ ------\\ r=40\\ \theta =\frac{1}{8} \end{cases}\implies s=40\cdot \cfrac{1}{8}\implies s=5$