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Pies Are Square? A Yummy Pi Day Lesson

I have a confession to make: I have been taking pi for granted. Although I am a lover of pie and pi (it comes with working for a math organization), I've never given much thought to that mysterious little math symbol which is often represented by the lower-case Greek letter π.


Now, you might know that pi is an irrational number - a decimal with no end and no repeating pattern. You might also know that pi is approximately 3.14, one of the most well-known mathematical constants, and is the ratio of a circle’s circumference to its diameter.

Many of us remember from middle school or earlier, that the area of a circle = πr². If you're like me though, you might not be able to communicate what πr² means or explain why it's the area of a circle. πr² is an equation I memorized to pass my geometry tests and until now, that was enough. But not anymore!

In celebration of this year's Pi Day, I wanted to truly understand why πr² is the equation we use to calculate the area of a circle. Luckily, my good friend, colleague, and content designer here at MIND - Nina Wu - is always willing to help me learn.


Every year, Nina bakes a pie to celebrate Pi Day and the mathematical connections we can make to the world around us. This year, Nina baked a special, square pie! How does a square pie relate back to pi and the area of a circle? Well, you'll have to watch the fantastic video lesson she put together below to find out! 


If you feel inspired to bake your own pie (circle or square) after watching Nina's Pi Day lesson, we'd love to hear from you! You can tweet us @MIND_Research or tag us on Instagram @STMath. Let us know how you're celebrating math this March 14, 2021.

Want to bake the same flavor pie as Nina? Find the recipe here.

Happy Pi Day, friends!

Other Ins(pi)ring Activities:

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Parker Erickson

About the Author

Parker Erickson was MIND’s Content and Community Specialist. As a digital storyteller, Parker is passionate about building strong communities through technology and social media. Off the clock, you can find him buried in the latest issue of The New Yorker or experiencing different cultures through food.


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