ABSTRACT
The relationship between angle in radians (θ), arc length (s) and radius of a circle (r) is: s = rθ (13.1) Since the arc length of a complete circle is 2πr and the angle subtended at the centre is 360°, then from equation (13.1), for a complete circle,
2πr = rθ or θ = 2π radians Thus, 2π radians corresponds to 360° (13.2)
as stated in Chapter 1.
