It’s finally here, the day you’ve been waiting for! A day when you can celebrate a beautiful theorem discovered nearly 2500 years ago. Better make good use of 8/15/17 because another Pythagorean Theorem Day won’t come around for over three years (look out for 12/16/20). Read on to learn more about the man, the theorem, and how to celebrate!

## Who was Pythagoras?

Pythagoras (569-500 B.C.E.) was born in Greece and devoted much of his life to the study of mathematics. He founded the Brotherhood of Pythagoreans who believed that numbers ruled the universe. The Pythagoreans gave numerical values to many objects and ideas, and sometimes these numerical values were endowed with mystical and spiritual qualities. Pythagoras took mathematics to a nearly religious level when, as legend has it, he sacrificed 100 oxen after discovering the theorem. The Pythagoreans also discovered irrational numbers and were so disturbed by the finding that they called these numbers “alogon,” which means “unutterable.” They attempted to keep the finding of irrational numbers confidential and even put a man to death for divulging the secret.

## It’s been a while since geometry. What’s the Pythagorean Theorem again?

The Pythagorean Theorem defines the relationship between the sides of a right triangle. According to the Theorem, in a right triangle, the square of the hypotenuse is equal to the sum of the other two sides. So, on August 15th, 2017, or 8/15/17, the square of the month and date equals the year squared: 8^{2} + 15^{2} = 17^{2}.

The theorem can be applied to many two-dimensional shapes to define area, and has broader application to computer science, physics, and even relationships in social networks!

## Most importantly, how can I celebrate Pythagorean Theorem Day?

Obviously, this is a great day to learn a little more about Pythagoras, and why his theorem is still relevant thousands of years later. Explore the real life applications: determine the biggest TV an entertainment unit can fit, calculate the distance of walking around a park vs. through it, or define the height a painter’s ladder needs to be so it won’t topple over.

All of that math will work up an appetite, so celebrate with some triangle-shaped food! Use the theorem to determine if two mediums or a large pizza will be bigger, then revel in the delicious beauty of a triangle in every slice.

**For more reading about the Pythagorean Theorem, check out these resources:**

“A Brief History of the Pythagorean Theorem.” Accessed on August 4, 2017. http://www.geom.uiuc.edu/~demo5337/Group3/hist.html

“Activity: Pythagoras’ Theorem.” *Math is Fun. *Accessed on August 4, 2017. https://www.mathsisfun.com/activity/pythagoras-theorem-shoes.html

Azad, K. “Surprising Uses of the Pythagorean Theorem.” *Better Explained. *Accessed on August 4, 2017. https://betterexplained.com/articles/surprising-uses-of-the-pythagorean-theorem/#Useful_Application_Conservation_of_Squares