Question

What is the measure of 0 in radians? In the diagram 0 is a central angle.

Answer 1

If the radius was 1, the angle θ is the arc length.  Here we have an arc length of 5 and a radius of 2, so an angle

θ = 5/2 radians

Not sure if they expect a fraction or a decimal.

Answer: 2.5 radians