The misconception that it's a variable comes in part from the fact that we often express circumference and area in terms of Pi.

Science Finding Pi Outside of the Circumference The number, which we celebrate on Tuesday, shows up more places than you might think.

As we celebrate again in 2018, here are some Pi Day facts you should know. What Is Pi? Pi represents the ratio of a circle’s circumference to its diameter.

What is Pi Day, and why do we celebrate it every March 14? Here's what to know as math lovers around the world mark Pi Day.

Time is a flat circle, Matthew McConaughey tells us, neglecting to explain how then we could measure time's circumference to derive its diameter, using pi. (Maybe it's best not to take the ...