regpoly-Abstract
Abstract Out of all prime-sided regular polygons, only 5 of them are constructible by CSE (compass and straightedge) construction, it is unknown whether more of them exist. 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40 etc. has been known since Ancient Greek. 17, 34, 51, etc. was proven constructible by Gauss. Out of all 98 n-gons from n=3 to n=100, only 24 of them constructible by CSE (see Gauss-Wantzel Theorem). Although for most basic geometric construction like perpendicular line, parallel line, midpoint construction, etc. CSE is feasible, it is not fundamental and has its own limits. Solutions of polynomial $$x^n-1=0$$ forms vertices of a regular \(n\)-gon in complex plane, inscribed in unit circle with one vertice being \(0+0i\) which is a trivial solution for polynomial above but notice that it factors into $$x^n-1=(x-1)(x^{n-1}+x^{n-2}+\cdots+x^2+x^1+1)$$