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.

Get complete chapter notes of chapter Trigonometric Functions including important concept, ... Pythagorean, co-function etc), law of sines, law of cosines, formula of area of triangles etc. ...

[3] θ-triangle and ω-parallelogram pairs with common area and common perimeter. Journal of Number Theory (2019). [4] Identities involving trigonometric functions and Bernoulli numbers .

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.