Graphing Calculator Math Worksheets Algebara Solver Chart Maker
 A+ A− B

## What is a Reference Angle?

Rules of Angles and Reference angle

Positive angles go in a counter clockwise direction. Below is a picture of a positive fifty degree angle
Evrey positive angle in quadrant I is already acute...so the reference angle is the measure of the angle itself:

To find the reference angle measuring x ° for angle in Quadrant III, the formula is $$180 - x^{\circ}$$ .

To find the reference angle measuring x ° for angle in Quadrant III, the formula is $$x - 180 ^{\circ}$$ .

To find the reference angle measuring x ° for angle in Quadrant IV, the formula is $$360 ^{\circ} -x$$ .

What is the reference angle for the angle in the graph below?

What is the reference angle for a 210° angle?

What is the reference angle for a 300° angle?