Pi is defined as the ratio of the circumference of a circle, to its diameter. It follows (how?) that the same constant pi is also the number of r x r squares that have the same total area as a circle of radius r (and so the area of a circle is given as (pi) multiplied by r^2).
In this 5 minute video, young Squeaky the Square discovers pi in his own uniquely square way! Please enjoy!
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