Detailed description of the problem of constructable regular polygons and a gloss of the proof. https://www.youtube.com/watch?v=EX7U0DGBmbM
A full explanation of the proof: https://www.youtube.com/watch?v=Gdy1u4lsjDw
There's a bit at the end showing the construction used in place of a building number on the front of the Mathematical Sciences Research Institute (MSRI) building at 17 Gauss Way, UC Berkeley.
Detailed description of the problem of constructable regular polygons and a gloss of the proof. https://www.youtube.com/watch?v=EX7U0DGBmbM
A full explanation of the proof: https://www.youtube.com/watch?v=Gdy1u4lsjDw