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.

At school we are told that the shape of a right-angled triangle depends upon the other two angles. The angle is related to the circumference of a circle, which is divided into 360 parts or degrees.

Two US college students, who discovered a new way to prove Pythagoras' famous 2,000-year-old theorem in 2022 have now come up with five different ways of solving the problem using trigonometry.

Pythagoras' famous 2,000-year-old theorem, summarized neatly as a 2 + b 2 = c 2, means that you can work out the length of any side of a right-angled triangle as long as you know the length of the ...

Calcea Johnson: So to start the proof, we start with just a regular right triangle where the angle in the corner is 90°. And the two angles are alpha and beta. Bill Whitaker: Uh-huh ...

“Trigonometric functions are based on sine and cosine, which are expressed as ratios of certain lengths of a right-angled triangle. It’s quite easy to get into a circular argument, ...