Method 3: Spirographs
The “Spirograph” is a geometric drawing toy that produces mathematical roulette curves of the variety technically known as hypotrochoids and epitrochoids. It was developed by a British engineer, Denys Fisher, and first sold in 1965.
The name has been a registered trademark of Hasbro Inc. since 1998 and was relaunched worldwide in 2013 by Kahootz Toys.
The Spirograph consists of two different-sized plastic rings and interlocking shape-segments (varied sized rings, triangles, and straight bars) each with gear teeth on both the inside and outside of their circumferences. Using a paper and pencil, they can be spun around to make an endless number of geometric shapes on the underlying paper.