Learn how to find the angles in right-angled triangles with this BBC Bitesize Maths article. For students between the ages of 11 and 14.

For a right-angled triangle, follow these steps to calculate the length of a side, x, when another side and an angle Ɵ is given: Label the two sides that contain information in the diagram with ...

I'm talking about trigonometry, of course: that bastion of angles and triangles that is essential to calculating velocity, momentum, and much more.