#### Answer

$\color{blue}{r \approx 17 \text{ m}}$

#### Work Step by Step

RECALL:
The area of a sector $(A)$ intercepted by a central angle $\theta$ on a circle whose radius is $r$ is given by the formula:
$A = \frac{1}{2}r^2\theta$, where $\theta$ is in radian measure.
Substitute the given values of the the central angle and the area of the sector to obtain:
$A=\frac{1}{2}r^2\theta
\\64=\frac{1}{2}(r)(\frac{\pi}{6})
\\64=r(\frac{\pi}{12})
\\\frac{\pi}{12} \cdot 64=r
\\16.75516082 =r
\\\color{blue}{r \approx 17 \text{ m}}$