Special Triangles

An Introduction to the Unit Circle

Abstract

This activity on the 45°-45°-90° triangle and the 30°-60°-90° triangle is designed to develop the building blocks to complete the Unit Circle, and in turn, to know the values of the functions sine and cosine for 16 special angles.

Within the activity are instances where you will want to be familiar with simplifying square roots (or as it is sometimes called, simplifying 'radicals'). You may wish to remind yourself of these simplification rules prior to this activity.

Level: High School or Undergraduate
Setting: Classroom
Activity Type: Learning Cycle
Discipline: Mathematics
Course: Trigonometry
Keywords: Unit Circle, Pythagorean Theorem, median, altitude, perpendicular bisector