Answer
$6 \text{ feet}$
Work Step by Step
$\because s = r \theta$
where
$s$: Length of the arc of the circle
$r$: Radius of the circle
$\theta$: Central angle that subtends the arc (in radians)
Use the formula above to obtain:
$r = \dfrac{s}{\theta}$
$r= \dfrac{2}{\frac{1}{3}} = 2 \cdot 3 = \boxed{6 \text{ feet}}$
