Coterminal and reference angles worksheet for Algebra 2
Coterminal angles land in the same place, so add or subtract whole turns. A reference angle is the acute angle to the x-axis, which is what makes every trig value in any quadrant computable from the first one.
Also taught in Precalculus, at its own level and with its own examples.
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Sigma Prep · sigmaprep.io/worksheets Name Coterminal and Reference Angles Date Period Answer each question.
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Sigma Prep · sigmaprep.io/worksheets Name Coterminal and Reference AnglesAnswer keyVersion 1 Date Period Answer each question.
Free math worksheets at sigmaprep.io/worksheets© 2026 Sigma Prep |
How to do these
Find the reference angle:
- 210 is in the third quadrant.
- The reference angle is the distance to the x-axis.
- 210 minus 180.
The answer is .
Where students go wrong
Measuring the reference angle from the y-axis, or subtracting from 360 in the wrong quadrant. It is always to the nearest part of the x-axis, so the answer is always between 0 and 90.
Also called positive coterminal angle or finding reference angles.
What you can put on this worksheet
- Coterminal angles
- Find the coterminal angle in : →
- Reference angles
- What is the reference angle of ? →
- Which quadrant an angle ends in
- In which quadrant, or on which axis, does end? → Quadrant III
- Sketch an angle in standard position
- Sketch in standard position. Where does its terminal side lie? — axes for sketching an angle → Quadrant III
- Coterminal angles in radians
- Find the coterminal angle in : →
- Reference angles in radians
- Find the reference angle of . →
- Negative and radian angles, read from a drawing, coterminal or not
- Find one positive and one negative coterminal angle:
→ - Angles with a given reference angle
- List four angles between and , one in each quadrant, with reference angle → For example:
- The whole angle from a drawing, in radians
- Find the measure of the angle, in radians. — an angle in standard position, labeled x, y, π/4 →