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

Two high school seniors have presented their proof of the Pythagorean theorem using trigonometry — which mathematicians thought to be impossible — at an American Mathematical Society meeting.

Two US college students discovered five new proofs of Pythagoras' theorem using trigonometry, expanding the theorem's understanding in a published study.