We give different answers. Someone polyhedrons are interesting only from an aesthetic point of view; someone sees the elements of the school course of stereometry.
In the book by Alexey Savvateev “Mathematics for the humanities. Live lectures" we found the answer to a similar question about the practical application of mathematics, which we found.
Quote from the book:
“Listener: is it true that the Ferm theorem has no practical use?
Alexey Savvateev: And who knows? This may have something to do with the physical models of the world. In fact, the last interesting thing is mathematics. Mathematics is, in a sense, akin to real religion. This is the last thing that interests mathematics. If this helps someone, mathematics is not particularly interesting. People who do mathematics have a completely different mood. These are other people. What, for example, are different teachers and officials. The same with mathematicians. These are two different people. "