If you cut out the yellow shape here, you can fold it up along the red lines, and all 11 sharp tips will meet at one point! You’ll get a polyhedron with 12 corners, tiled by equilateral triangles. 5 triangles meet at each corner. There are also places where 6 triangles meet: these places are flat. Some triangles get folded along the red lines.
This is a companion discussion topic for the original entry at https://johncarlosbaez.wordpress.com/2024/10/25/triangulations-of-the-sphere/