Identify the reference angle ø for each given angle, theta. when theta= 300 degrees, ø= when theta= 225 degrees, ø= when theta= 480 degrees, ø= when theta= -210 degrees, ø=

∅ = 60
∅ = 45
∅ = 60
∅ = 30

For a 300° angle, it lies in Quadrant IV; therefore we subtract it from 360:
360-300 = 60

For a 225° angle, it lies in Quadrant III; therefore we subtract 180 from it:
225-180 = 45

For a 480° angle, it will lie in Quadrant II (it will lie in the same place as 120°); therefore we subtract it from 180:
180-120 = 60

For a -210° angle, it will lie in Quadrant II (it will lie in the same place as 150°); therefore we subtract it from 180:
180-150 = 30