Exact Trigonometry Functions for Selected Acute Angles

By Mary Jane Sterling

Part of Trigonometry For Dummies Cheat Sheet

Using the lengths of the sides of the two special right triangles — the 30-60-90 right triangle and the 45-45-90 right triangle — the following exact values for trig functions are found. Using these values in conjunction with reference angles and signs of the functions in the different quadrants, you can determine the exact values of the multiples of these angles.