That's the Pythagorean theorem, which shows that in a right triangle, where the shorter legs are a and b, the sum of their squares is equal to the square of the longest leg, the hypotenuse, c.

A high school teacher didn't expect a solution when she set a 2,000-year-old Pythagorean Theorem problem in front of her students. Then Calcea Johnson and Ne'Kiya Jackson stepped up to the challenge.

At an American Mathematical Society meeting, high school students presented a proof of the Pythagorean theorem that used trigonometry—an approach that some once considered impossible ...