Trigonometry visual reference
Unit Circle Chart: Degrees, Radians & Trig Values
The unit circle turns an angle into a point: the x-coordinate is cosine and the y-coordinate is sine. This chart groups the standard angles by quadrant so signs and reference-angle patterns stay visible.
How to read it
Use the chart as a decision tool.
A complete unit circle chart with degrees, radians, ordered pairs, and exact sine and cosine values, plus a blank printable practice circle. Read the label first, identify the matching structure in your problem, then confirm that any stated conditions apply before substituting values.
How the coordinates work
Every point on the unit circle has radius 1.
Pythagorean identity
Quadrant signs
Use the reference angle for magnitude and the quadrant for signs.
Quadrant I
Quadrant II
Quadrant III
Quadrant IV
How to remember it
Memorize one quadrant, then use signs
- 1Learn 0°, 30°, 45°, 60°, and 90° first.
- 2Cosine is the x-coordinate; sine is the y-coordinate.
- 3Reflect the first-quadrant values and apply the quadrant sign pattern: all, sine, tangent, cosine.
Printable practice
Blank unit-circle practice chart
Print the unlabeled circle and fill in degrees, radians, coordinates, sine, and cosine from memory.