The 9-sided Enneahedron - Numberphile
Christian Lawson-Perfect on creating the Herschel Enneahedron. See the free trial from episode sponsor Brilliant - https://brilliant.org/numberphile -- More links & stuff in full description below ↓↓↓ Christian at Newcastle University - https://www.staff.ncl.ac.uk/christian.perfect/ And mathstodon ...