Pi Day celebrates the mathematical constant (π), as March 14 can also be expressed as 3.14, the first three digits of pi. Pi is the ratio of a circle’s circumference to its diameter, which is a constant. That is – for any size circle, the ratio is the same (π).

The first large-scale celebration of Pi Day was organized by Larry Shaw at the San Francisco Exploratorium, where Shaw worked as a physicist. Then in March 2009, Pi Day became a national holiday in the United States. And a fun note? March 14th is also Albert Einstein’s birthday. Don’t worry, unlike Pi, this history lesson won’t go on forever. Onto the math!

### These two warm-ups can be used for a quick check

of student understanding with trigonometric expressions:

You can run any of these as a warm-up, quiz or even assign for homework. You can also copy and modify the questions and make them your own. There are lots of excellent ideas to leverage for your classroom. With Woot Math, all of the polls are completely free and a great Open Educational Resources (OER).

Get started by clicking on any of the polls now to preview them, or login to wootmath.com and search by name. You can also click on the categories in the Shared Gallery – for example– Geometry, Trigonometry, to find more great resources for your classroom. And who knows, you might also have fun with pie charts, or even pumpkin pie.