## Have Your Pi and Eat It Too on Pi Day

March 14 is Pi Day again. We wrote about it last year, and here we are writing about it again.

But before you start to yawn, we want to point out something pretty amazing, which is that we have some new things to say about Pi this year, thanks to a free new video entitled “What is the value of Pi?” that StraighterLine has just made available on Youtube. Let’s take a closer look . . .

*Here are some facts that you probably knew before you watched our new video...*

- March 14 – which can be written as 3/14 – is Pi Day because it the number Pi is usually presented as 3.14. Get it?

- Pi is a number that is equal to the value of the ratio between a circle’s circumference and its diameter.

- The neat thing about Pi is that it is the same for any circle – whether it’s a Frisbee, a homemade pie (like the one you’ll see in our Pi video), or your wedding ring. That’s because it’s a ratio, not a measurement of a particular circle.

- To find the area of a circle, the formula is Pi x R
^{2}. (Pi times the radius squared.) That means that to find the area of a circle, you first measure the length of its widest point across (the diameter), divide that in half (that tells you the radius), and multiply the result times Pi (3.14). You now know the area of your circle.

- To find the circumference of a circle, the formula is Pi x D. (Pi times the diameter.) That means that you have to measure the width of the circle at its widest point (the diameter) and multiply that times Pi (3.14). Viola! You now know the distance you will have to go if someone makes you walk around something big and round, like a huge Pie that was baked by Brownies for a county fair.

*And here are some facts about Pi that you probably didn’t know before you watched our new video . . .*

- Pi is an “irrational number.” That means you can roll Pi out to 3.141593 and beyond.

- Pi goes on forever. You can keep adding numbers infinitely to the right of the decimal point and it will just never stop.

- Pi Day is only the start of the fun, because Pi goes on forever.

What’s the best way to celebrate Pi Day? Go get a pie and eat it while you calculate its area and circumference as you watch the new StraighterLine Pi video, that’s how.

**Related - **Online Mathematics Courses