Irregular polyhedra

[Philip Davies]

Thanks. I knew that I could rely upon you. However, the first block, of 5, has minimum 7 facets, each of which could theoretically be the base. (It was a mistake to say that the stacking order was predetermined) Each of the 5 blocks could form the first base. I understand that the blocks could be arranged 120 ways. But each has 7 facets, any one of which could be the first to form the base. Pardon me, since I don’t remember the maths I learned 50 years ago, and also been on my feet for 13 hours. initially I thought that would be 7! X 5! Have I missed something?