Learn about three trigonometric ratios in similar right-angled triangles with this BBC Bitesize Maths article. For students between the ages of 11 and 14.

Trigonometry close trigonometryThe study of sides and angles in triangles. can be used to find a missing angle in a right-angled triangle when two sides are known. An understanding of the three ...

A 3,700-year old Babylonian clay tablet reveals an ancient method of constructing right-angled triangles that makes it the world’s oldest and most accurate trigonometric table.