This model is a simple hinged equilateral triangle.  Each side of each triangle can be interlocked with another triangle forming a hinge. These pieces can be combined to form more complex models.  I have attached photos of some the models I have built with these hinged triangles. The .3mf file includes one plate of 20 triangles as a single hinged triangle by itself is not particularly useful.  This design is the result of a number of iterations of ways to build the hinges.  This version supports fairly simple and quick assembly and disassembly of more complex models, has pretty good durability and reusability of the triangles, and does not take too much filament per triangle (a bit over 2.5 grams).   

Here are links to some short videos talking through the using this model:

1. Quick look at the basic units and how they can and unlink:  [https://www.instagram.com/reel/DFMkQFdP0-H/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMkQFdP0-H/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

2.  Simplest “solid” from the triangles: [https://www.instagram.com/reel/DFMk6sXPZgJ/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMk6sXPZgJ/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

3. Building more complex polyhedrons - octahedron, icosahedron, stellated icosahedron: [https://www.instagram.com/reel/DFMlJ_Tvpf0/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMlJ_Tvpf0/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

4.  Showing a flat grid of triangles and folding into a tube of polygons: [https://www.instagram.com/reel/DFMloi9vA2X/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMloi9vA2X/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

5. From a tube to a torus to a five pointed star: [https://www.instagram.com/reel/DFMlxQ0vsPj/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMlxQ0vsPj/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

6. A helix from the same elements as the torus: [https://www.instagram.com/reel/DFMl83bPvkl/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMl83bPvkl/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)

    

7. Combining multiple torus objects to form a symmetric object of six interlocking toruses: [https://www.instagram.com/reel/DFMmNsMve_u/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==](https://www.instagram.com/reel/DFMmNsMve_u/?utm_source=ig_web_copy_link&igsh=MzRlODBiNWFlZA==)