The Pythagorean theorem (a² + b² = c²)

From Oxford Mathematics

Robin Wilson's third talk on the equations that make mathematics brings us to right-angled triangles and to the Pythagoreans and their successors. You can watch other episodes in the series here: https://www.youtube.com/playlist?list=PL4d5ZtfQonW0yqeFK__FirrjjmcQFpyye Robin's book 'Sum Stories: Equations and their origins' is also available here: https://www.amazon.co.uk/Sum-Stories-Equations-Their-Origins/dp/0199607907