Blank unit circles with the 16 special angles marked, labelled in degrees, radians or exact coordinates.
The unit circle has radius 1, so the coordinates of each point are the cosine and sine of its angle. Students learn the 16 special angles by writing their radian measures and exact coordinates on the circle. The blank version works as a self-check quiz.
Ask students to fill in the first quadrant from memory, then use the symmetry of the circle to fill in the rest.