March 14^{th} is Pi Day!

Today is also the birthday of Albert Einstein (1879-1955).

Pi is the irrational number π = 3.1415926535…

The first three digits of pi coincide with the U.S. mm-dd-yy date format of 3/14 for Pi Day.

Pi is calculated as the circumference of a circle, divided by its diameter.

Celebrate Pi Day by drawing circles with this online spirograph tool! “**Inspirograph**”

These circle designs are called hypotrochoids. A hypotrochoid is a curve drawn by rolling one circle around inside another stationary circle.

My Spirograph Drawing:

What shapes can you make? Creating the different shapes reminds me of cutting out snowflakes.

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Oh, I remember spirograph sets. Your design came out pretty!

Thanks, Marcia!