A circle has an arc of length 24π that is intercepted by a central angle of 80°.What is the radius of the circle?
The answer is 54
We have
Arc Length = 2pi * r * ( Given Angle / 360 ) .....so...
24 pi = 2 pi * r * (80 /360) divide out pi
24 = 2 * r * ( 2/9)
24 = (4/9) * r multiply both sides by 9/4
24 (9/4) = r = (24/4) * 9 = 6 * 9 = 54 in
+912 
