# What letter is pi in the Greek alphabet? (Pi day!)

National Pi Day has significance if you happen to be a 5th grade math teacher (or 5th grade math student). But what does it mean to the average person, and what is it, exactly?

Pi is the 16th letter in the Greek alphabet, which has 24 characters, just like that of the standard English one. The numeric representation of pi (3.14…..) is equal to the circumference of a circle divided by its diameter. Always. You don’t have to be a mathemagician or a nerd to be fascinated by this truism. What’s weird about it is that no one even knows the origin of this realization. It has been said that the building of the pyramids would not have been possible without pi. The final value of pi is infinite, which is pretty hard to wrap your mind around, but the truth is it doesn’t matter, because it’s only an estimate, and using 3.14 works well enough for whatever we need to calculate, whether it’s measuring the circumference of a table leg that needs replacing, or more complicated applications in architecture, for example.

Celebrate National Pi Day by eating a pizza, or if you’re like us, by pontificating on Archimedes, Newton, and the enneacontakaihexagon (look it up).