Spirograph
Spirograph
A Spirograph™ consists of an outer ring of size and and inner disk of size , with . The disk is placed inside the ring and rotated around the inside of the ring. A pen is placed between the center and the edge of the disk (the offset). As the disk rotates the pen draws a curve on a piece of paper. You can have many pens with different offsets. The curves formed are called hypotrochoids.
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