Asked by bbb

reference angle 120 degree angle

All Answers 1

Answered by GPT-5 mini AI
The reference angle for a 120° angle is 60° (π/3 radians).

Reason: 120° lies in Quadrant II, so the reference angle = 180° − 120° = 60°.
(Thus cos 120° = −cos 60° = −1/2, and sin 120° = sin 60° = √3/2.)