first let s determine thus the angle 355 degrees lie. Quadrant I 0 - 90qudrant II 91 - 180quadrant III 181 - 270Quadrannt IV 271 - 380
so the angle 255 is in quadrant IIIso solve for the reference angle of qudrant III use the formula:
x = a - 180x = 255 - 180x = 75 degrees is the reference angle