Every year on March 14th, teachers, scientists, and those who just love math and numbers celebrate Pi Day, a special day that pays tribute to Pi… otherwise known as the number 3.14 (plus a bunch of other digits that are really hard to memorize). But unless you’re a math teacher, you might not know why that number is represented by a certain symbol. So what does the Pi symbol mean?

In case it’s been awhile since you sat down in a math class, Pi is the ratio of a circle’s circumference to its diameter, and it’s represented by the symbol π, which, just by looking at it, doesn’t seem to relate much to the definition or the number that it represents.

## But the meaning behind that symbol goes a little further. According to Live Science, the Pi symbol is meant to represent the idea of Pi as it pertains to a river.

So the symbol itself is showing the straight line connection between two bends in a river, which is actually pretty cool — and that connecting line is also showing the diameter. Mind = blown.

Pi is, by definition, an irrational number, so it makes sense that it would relate to something else you can’t control, like a river. Math and science can often seem pretty intimidating, especially if they’re not your best subjects. But even something as simple as a Pi symbol is kind of beautiful, isn’t it?