3. The length of arc EF is 5 in. Find
the length of the radius.

Answer:
radius = 30 in
Step-by-step explanation:
EF = circumference × fraction of circle, substitute values
5π = 2πr × [tex]\frac{30}{360}[/tex] ← where r is the radius
5π = 2πr × [tex]\frac{1}{12}[/tex]
Multiply both sides by 12 to clear the fraction
60π = 2πr ( divide both sides by 2π )
[tex]\frac{60\pi }{2\pi }[/tex] = r, thus
r = 30 in