Explanation:
remember, 360° (the full circle) = 2pi
a)
60° = 60/360 × 2pi = 2pi/6 = pi/3 = 1/3 × pi =
= 1.047197551... ≈ 1.047
b)
210° = 210/360 × 2pi = 210/180 × pi = 7/6 × pi =
= 3.665191429... ≈ 3.665
c)
225° = 225/360 × 2pi = 225/180 × pi = 45/36 × pi =
= 5/4 × pi = 3.926990817... ≈ 3.927
d)
120° = 120/360 × 2pi = 2pi/3 = 2/3 × pi =
= 2.094395102... ≈ 2.094