Celebrate Pi(nt) Day With This Mathematical Bar Bet

This one has been around for a while, but hey, any reason to have a good pint of beer, right?

When you’re sitting with a friend and a couple beers in pint glasses in front of you (mostly drained), propose this counter-intuitive fact: the circumference of the base of the glass is actually longer than the glass is tall. How could this be? It’s obviously so much smaller!

Easiest way to prove this is, once the glass is empty of course, take a napkin and wrap it around the base of the glass, pinching it off once you’ve encircled it. Then take that length and hold it straight against the vertical side of the glass. It will be nearly an inch longer.

There’s no magic, just math. Intuitively we look at the base of the glass and see the diameter, which is much smaller than the height. But you have to multiply that diameter by pi (3.14159…) to get the circumference, which makes a big difference.

Happy Pi(nt) Day!

[Fun fact: a Pi of Pints would be 50.26548245743… ounces of beer.]