Tetrahedral Spikey, Tetrahedron

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Tetrahedral Spikey: Each side of the large equilateral triangle measures approximately 86mm in length. A raft will be necessary for printing, but support is not required. To create this design, start with an equilateral triangle and extrude it at a tapering angle of -19.4712 degrees, which can be calculated by subtracting 90 degrees from the arccosine of 1/3. This process should be repeated for each central triangle on the four faces of the tetrahedron. This project is an excellent way to introduce students to the world of 3D design, and a basic understanding of trigonometry will come in handy. However, please note that the spikey can pose a danger to small children, so it's essential to use flexible filament when possible. References: 1. https://en.wikipedia.org/wiki/Tetrahedron 2. http://mathworld.wolfram.com/Spikey.html