A high school teacher didn't expect a solution when she set a 2,000-year-old Pythagorean Theorem problem in front of her ...

A short video showing how to find right-angled triangles in other shapes to help solve geometry problems.

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.

The Museum of Math flipped this idea around — if the lengths of the sides of a triangle, like the Flatiron building, satisfy the Pythagorean theorem, then the triangle must be a right triangle.