August 15, 2017 (8/15/17) was Pythagorean Theorem Day (see I missed Pythagorean Theorem Day). I was not even aware that there was such a day until this year, but it brought to my attention some really ...

But that isn’t quite true: in our lecture we present a new proof of Pythagoras’s Theorem which is based on a fundamental result in trigonometry—the Law of Sines—and we show that the proof is ...

This is an updated version of a story first published on Nov. 1, 2024 For centuries, students have learned that in a right triangle, the square of the hypotenuse equals the sum of the squares of the ...