The polyhedra shown above and below are duals. The one above has 1800 faces and 960 vertices. The one below has 960 faces, and 1800 vertices. This “flipping” of the face and vertex numbers always happens with dual polyhedra.

Also, two dual polyhedra always have the same number of edges, which can be found by subtracting two from the sum of the numbers of faces and vertices (this is based on Euler’s Formula, F + V = E + 2). In this case, each of these polyhedra have 1800 + 960 – 2 = 2758 edges.

These virtual models were created using Stella 4d: Polyhedron Navigator, software you can try for yourself right here.

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