Find the radius of the circle.

Question

Answer 1

Use S = rθ where S is the arc length which is 11π, r is the radius, and θ is the angle which is 3π/5 so:

11π = (3π/5)r or r = (11π)/(3π/5) = 11π•5/(3π) = 55/3

Answer 2

Measure of central angle is equal to measure of subtended arc (from Geometry)

3π / 5 = 11x