Find the length s of the arc of a circle of radius 55 inches subtended by the central angle 78*

Question

Radius is 55 inches, subtended by 78 degrees

Answer 1

central angle = arc length

------------------ --------------

360 circumference = 2 * PI * R

78 = arc length

----- ------------

360 2 * PI * 55

cross multiply and solve for arc length

Answer 2

The subtended arc will be the same fraction of the circumference as the angle is of 360°

78/360 = s/(2πR) or 2πR (78/360) = s