the tutorials below, show examples on how to model* the five convex regular polyhedra:
These and other examples on how to model them are included in my Doctoral Thesis (in Portuguese).
regular tetrahedron, T
regular hexahedron (cube), C
rhino’s command box allows you to model a cube quite easily. Just select the tool, locate the point in which the cube is to be drawn (first corner or base), type the edge lenght, type enter for the width and enter again for the height. this will ensure that every edge lenght of the box is the same.
regular octahedron, O
regular dodecahedron, D
regular icosahedron, I
* the software used is Rhinoceros (version 6.0)