The goal of this lesson is for students to identify radian angles and the coordinates associated with those angles on the unit circle. In doing so, this draws special attention to the symmetry of the - and -coordinates of points on the unit circle. 

From just a few starting angles, students identify and label a unit circle with 24 angles that are each apart. Then students shift their thinking from angles to the coordinates associated with those angles. The work here leverages the symmetry inherent in the unit circle and students can take advantage of repeated reasoning as they label the coordinates of all 24 points (MP8).

During the Lesson Synthesis, students create visual displays of the unit circle. Post these in the classroom for student reference throughout the remaining lessons of the unit. In later lessons, students use the work here to extend their understanding of the domain of cosine, sine, and tangent to all real numbers.