15 votes The Sydler π/4 polyhedron. The shape that should be impossible. Posted June 8 by cfabbro Tags: mathematics, geometry, jean pierre sydler, polyhedrons, hilberts third problem, angles.dihedral, matthias goerner, modeling.3d, printing.3d, interviews, robin houston, author.matt parker, videos, standup maths https://www.youtube.com/watch?v=daVny9y72UE Link information This data is scraped automatically and may be incorrect. Authors Stand-up Maths Duration 26:01 Published Jun 5 2024