UNIT CIRCLE — REFERENCE ANGLES

Created by Albert Chosenko

What is a reference angle?
The acute angle between the terminal side and the x-axis

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TermDefinition
What is a reference angle?
The acute angle between the terminal side and the x-axis
What is the reference angle in Quadrant I?
θ
What is the reference angle in Quadrant II?
180° − θ
What is the reference angle in Quadrant III?
θ − 180°
What is the reference angle in Quadrant IV?
360° − θ
What is the reference angle of 150°?
30°
What is the reference angle of 210°?
30°
What is the reference angle of 330°?
30°
What is the reference angle of 135°?
45°
What is the reference angle of 225°?
45°
What is the reference angle of 315°?
45°
What is the reference angle of 120°?
60°
What is the reference angle of 240°?
60°
What is the reference angle of 300°?
60°