2005/10/01 by David A. Cox, Jerry Shurman · 3 citations
Mathematics · #Algebraic Geometry and Number Theory #Finite Group Theory Research #Geometric and Algebraic Topology #Geometry #Mathematics #Physics
paper · doi:10.1080/00029890.2005.11920241
openalex publication_date 2005/10/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
(x 2 + y 2) 2 = x 2 − y 2 pictured in Figure 1, can be divided into n arcs of equal length by straightedge and compass if and only if n is a power of 2 times a product of distinct Fermat primes [1, p. 314]. By an earlier theorem of Gauss, these are exactly the values of n for which a regular n-gon is constructible by straightedge