Education Technology

Mathematics lessons for IB® Diploma Programme

Analysis and Approaches | Geometry and Trigonometry


Unit Circle

Activity Overview

Students discover the relationship between the trigonometric functions of sine, cosine, and tangent and the side length ratios of a right triangle.

Key Steps


Step 1

Students engage in an exploration of points and angles on the unit circle.

Right triangle relationships are utilized to develop the relationship between angles and coordinates.


Step 2

Students link their prior knowledge of special right triangles to identify coordinates for 30, 45, and 60 degree angles on the unit circle.


Step 3

After establishing relationships in Quadrant I, students extend their knowledge through the application of symmetry to angles in Quadrants II, III, and IV.