This document provides information about trigonometry including: 1) Conversions between degrees and radians, definitions of sine, cosine, and tangent, and trigonometric ratios. 2) Values of trigonometric functions for special angles like 0°, 30°, 45°, 60°, 90°. 3) Relations between trigonometric functions of complementary, coterminal, and reference angles. 4) Formulas for sum and difference of trigonometric functions. 5) Graphs of sine, cosine, and tangent functions.