Unit Circle
A unit circle is a circle with a radius equal to one (1) unit.
The circle is portioned into sectors based on the special right triangles 30°-60°-90° and 45°-45°-90°. These are the grey lines within the circle.
To see the Degree measures check the Degrees check box. Radian measures use the Radian check box. When you select the Coordinate value, these are the cosine and sine values of the special right triangles 30°-60°-90° and 45°-45°-90°. Use the "tri-" sliders to view how these special right triangles fit on the unit circle. See Unit Circle Triangles for additional information.
Select each check box separately to see and learn the values described. Memorize the whole Unit Circle.