Question

reference angle and coterminal angle of 5pi 5pi/3 , - 6pi/5

Answer 1

5pi = 6pi - 5pi = pi
Reference angle of 5pi = pi - pi = 0

Reference angle of 5pi/3 = 2pi - 5pi/3 = pi/3

-6pi/5 = 2pi - 6pi/5 = 4pi/5
Reference angle of -6pi/5 = (pi - 4pi/5) = pi/5