Icosahedron Model, Pedagogically Stretched

cults3d

Icosahedron Model, Pedagogically Enhanced i is for Icosahedron (Regular or Platonic) The present design empowers students to create their own Platonic icosahedron models and then explore and interact with it for deeper mathematical understanding such as the three orthogonal golden rectangles. By the way, it rotates smoothly once assembled! To engage with the geometric structure of the icosahedron, one needs some elastic cords like those used for name badges (with some rigid end covers), 12 vertices, and 30 edges. The inner edges of the connectors are trimmed for easy assembly. To assemble the icosahedron, feel free to press the vertices against a hard surface or use a pair of pliers. Once assembled, it may be challenging to disassemble. If so desired, please use the loose vertex or increase the printing resolution. The regular vertex works well in my experiments at 0.18-0.20 mm, 10% infill, with PLA filament. Among the files 1. Two versions of vertices are available. The regular one functions well at 0.2mm resolution. 2. Edges of various lengths (50mm to 100mm) are provided, which should not be mixed up. All regular (Platonic) icosahedra have similar structures, don't they? 3. To build an icosahedron, one needs 12 vertices and 30 edges. Here is a simple question to entertain the kids in counting: Each vertex has 5 edges connected to it. There are 12 vertices. So there are 12 * 5 edges. But each edge is shared by two vertices. So there must be 60/2 edges. References http://www.froebelweb.org/web7000.html https://en.wikipedia.org/wiki/Regular_icosahedron