Angle Formulas in Trigonometry: Definition, Representaion, Questions & More Check definition and formulas for central angle, double angle and multiple angles.

Learn and revise trigonometric ratios of sine, cosine and tangent and calculate angles and lengths in right-angled triangles with GCSE Bitesize AQA Maths.

The three trigonometric ratios; sine, cosine and tangent are used to calculate angles and lengths in right-angled triangles. The sine and cosine rules calculate lengths and angles in any triangle.

Classical trigonometry calls the separation between two lines an "angle", which is the length of a circular arc between two lines.