To solve problems involving non-right-angled triangles, the correct rule must first be chosen. The cosine rule can be used in any triangle to calculate: a side when two sides and the angle in between ...

An animated guide to using trigonometry. Trigonometric terms are explained and examples are used to show how to find unknown angles and sides for right-angled triangles. Use as an introduction or ...

The class Trigonometry: Sine, Cosine, and Tangent discusses the three basic ratios that are the basis for trigonometry. Trigonometry is based on the specific relationships between the sides and angles ...