Answer
5.73 m
Work Step by Step
Given-
angle, $\theta$ = $\frac{5\pi}{6}$ rad
arc, s = 15 m
radius, r = ?
We know that -
r = $\frac{s}{\theta}$
= $ \frac{15}{5\pi/6}$
= $15\times \frac{6}{5\pi}$
= $\frac{18}{\pi}$ = $\frac{18}{3.14}$
= 5.73 m