Reference Angle Calculator
Find the reference angle, identify the quadrant, and discover coterminal angles.
Reference Angle Rules
Quadrant I (0° - 90°): Reference angle = θ
Quadrant II (90° - 180°): Reference angle = 180° - θ
Quadrant III (180° - 270°): Reference angle = θ - 180°
Quadrant IV (270° - 360°): Reference angle = 360° - θ