Happy Pythagorean Theorem Day. Celebrate While You Can. There Won’t Be Another for 79 More Years.

THE FXBG ADVANCE SATURDAY 10/24/26 MIDDAY READ

Steve Watkins, ADVANCE EDITOR

Pythagoras, who didn’t actually discover the theorem that bears his name, though he is still credited with inventing the Pythagorean cup, a practical joke and novelty item that works the same way as the siphoning mechanism inside toilets. He also refused to eat fava beans, supposedly because he believed they acted as a ladder to the underworld and might contain the souls of the dead.

From Khan Academy: “The Pythagorean theorem is a fundamental rule in geometry stating that for any right-angled triangle, the square of the length of the hypotenuse (the longest side, opposite the right angle) is equal to the sum of the squares of the lengths of the other two sides. Mathematically, it is written as a² + b² = c², where c represents the hypotenuse, and a and b represent the other two sides (legs).”

Or, to put it in simpler terms, “In any right triangle, the area of the square built on the longest side equals the sum of the areas of the squares built on the two shorter sides.”

Here’s a homemade 44-second demonstration, in case you’re having a hard time visualizing it:

However you want to put it, the University of Mary Washington Math Department got a jump on everybody Friday by celebrating Pythagorean Theorem Day a day early—too excited to wait, and worried that if they missed it, they’d all most likely be dead before the next one comes around.

Here’s how it broke down, according to Lisa Marvashti with UMW’s office of Media and Public Relations:

UMW students Joana Diaz, a biology major taking a course in calculus, and Luciana Amaya, a biomedical major, try some triangular-shaped slices of pizza at the UMW Department of Math’s celebration of Pythagorean Theorem Day. The day takes place this year on Oct. 24, 2026 (10² + 24² = 100 + 576 = 676 = 26²). The next Pythagorean Theorem Day will not occur until March 4, 2305.

Sweet treats (cut, of course, in triangles) were on the buffet for the UMW Math Department’s celebration of Pythagorean Theorem Day. All food served was in the shape of triangles to honor the theorem.

Spanakopita’s triangular shape made it an appropriate dish for the UMW Math Department’s Pythagorean Theorem Day celebration.

Professor of Math Suzanne Sumner and Department of Math Lecturer Keith Nabb pose in their Pythagorean Theorem T-shirts.

UMW Math students created art in honor of Pythagorean Theorem Day.