interesting... I also found a construction for a 17-gon

来源: 于 2011-01-17 11:58:12 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

File:Regular Heptadecagon Inscribed in a Circle.gif

This is the exact construction for a heptadecagon. Interestingly, all constructible regular polygons with an odd number of sides are part of a particular sequence: they are multiples of the five known Fermat primes.