Revise trigonometric ratios of sine, cosine and tangent and calculate angles in right-angled triangles with this BBC Bitesize GCSE Maths Eduqas guide.

The mathematical study of triangles has just got a whole lot simpler, according to a researcher who says his new theory of trigonometry is easier to use and more accurate.

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

Revise trigonometric ratios of sine, cosine and tangent and calculate angles in right-angled triangles with this BBC Bitesize GCSE Maths OCR study guide.