A Regular Rep Icosahedron of Order Four
Can a net of a regular icosahedron be cut into smaller polygons, each of which is itself a net of a regular icosahedron? Nomi, Shiota, Kamata and Uehara explicitly recorded this existence question in 2025. We give an affirmative answer with four equal-area pieces. The outer net is a polyiamond of eighty unit equilateral triangles and folds to an icosahedron of edge length 2; each twenty-triangle piece is an edge net of one of edge length 1. Two noncongruent small-net shapes occur twice each. The search uses a half-turn of the subdivided icosahedron to find a surface cover, followed by a separate search for a compatible planar development. We present the exact construction and a standalone verifier that checks geometry, topology and every folding identification using integer arithmetic.
Authors
- John Seamons
Publication Details
- Journal
- Zenodo (CERN European Organization for Nuclear Research)
- Published
- 2026-10-29
- DOI
- https://doi.org/10.5281/zenodo.23750175
- Primary Topic
- Mathematics and Applications
- Type
- preprint