This is an updated version of a story first published on Nov. 1, 2024 For centuries, students have learned that in a right ...

It’s not clear whether he or his disciples came up with his eponymous theorem. But the principle is a mainstay of math class and enables the calculation of the length of any side of a right-angled ...

In this triangle \(a^2 = b^2 + c^2\) 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 or not.

We investigate here the representability of integers as sums of triangular numbers, where the n-th triangular number is given by Tn = n(n+1)/2. In particular, we show ...