Maths

Pythagoras' Theorem states that for all right-angled triangles, 'The square on the hypotenuse is equal to the sum of the squares on the other two sides'. (The hypotenuse is the longest side and it's always opposite the right angle) So for any right-angled triangle the square on the hypotenuse is equal to the sum of the squares on the other two sides  In this triangle a² = b² + c² and angle A is a right angle.  Pythagoras' Theorem only works for right-angled triangles, so you can use it to test whether a triangle has a right  angle.