# Why We Celebrate Pi Day On 14th March

Photo: RooM the Agency/Alamy Stock Photo.
Today is an marks an important annual celebration: Pi Day. I don't blame you if you only associate 14th March, or 3.14, as the numerical sequence begins, with a pie that has the Greek symbol etched into it. (My personal favourite is cherry or strawberry with a lattice crust.)
But Pi Day is about so much more than sweet treat with fruity preserves and fresh whipped cream. And you don't have to be a mathematician to appreciate the number's significance.
Let's throw it back to the OG days of elementary school. You might recall that Pi is the ratio of a circle's circumference (the distance around) to its diameter (its width). It is a constant in the sense that it applies to all circles, no matter their size, but it is also infinite. We think of it as 3.14, but so far, it is has been calculated to 10 trillion decimal places.
The reason that mathematicians geek out over Pi is because although the number seems random and unpredictable, its relation to a perfect circle means that it shows up everywhere. From calculations involving the length of a river to the volume of a cylinder, Pi is inescapable in the world around us.
And for those who say that Pi Day is just another fake holiday (a la National Tartar Sauce Day), know this: In 2009 the House of Representatives passed a resolution officially recognising the day. So today, in between bites (or 'grams) of banana cream pie, take a moment to share some knowledge about Pi itself — or at least appreciate the beauty of a circle.