Angles and Length: Arc Length Given $r$ and $\theta$

Difficult

If $s$ denotes the length of an arc of a circle of radius $r$ subtended by a central angle $\theta$ , find the missing quantity $$s=\text{ ?}$$ $$ r=9\text{ ft}$$ $$ \theta =\cfrac { \pi }{ 3 }$$ Round your answer to four decimal places.