Question

A circle has a radius of 12ft . find the length s of the arc intercepted by a central angle of 9° .

Answer 1

Plug in the values into the base equation; 

$l=2 \pi r( \frac{ \alpha }{360} )$ <-- alpha is the degree 

l=2 \pi (12)(9/360) 
l=1.88495 ft ≈ 1.90 ft 

Hope I helped :)