Use cast rule
120 degrees is in the Quadrant 2 meaning it is in the “S” quadrant AKA where Sin is positive, Cos is negative, & Tan is negative.
I found the angle of the coterminal by subtracting 120° from 180° -> 180-120=60°
Then I used the 30°-60°-90° triangle rule to find my lengths and ratios for sin, cos and tan!
