Happy Perfect Square Day!

Today’s date—9/16/25—is a rare and exciting moment in math history. Why?

Each part of the date is a perfect square:
9 = 3²
16 = 4²
25 = 5²
Even more amazing? These three numbers—3, 4, and 5—form a Pythagorean triple, which means they fit perfectly into the Pythagorean Theorem:
3²+4² = 9 + 16 = 25 = 5²

This is the classic formula used to find the sides of a right triangle—a key concept in geometry and real-world design.

What’s a Pythagorean Triple?
It’s a set of three whole numbers that make a right triangle when plugged into the formula:
a² +  b² = c² 
The triple (3, 4, 5) is the most famous example!

Why Today Is Extra Special
A date like 9/16/25—where all three numbers are perfect squares and form a Pythagorean triple—will only happen once in our lifetime. It’s a mathematically rare alignment that won’t repeat again in this format.
(Fun bonus: It turns out the full year, 2025, is also a perfect square: 45 times 45.)

So let’s celebrate the beauty of numbers and encourage our students to see math in the world around them—starting with today’s date!

#PerfectSquareDay #PythagoreanPower #MathIsMagical #91625