Fourier Construction of Regular Polygons and Star Polygons
Let be the coefficients of a Fourier expansion of a regular polygon with sides. This Demonstration plots the partial sums of the Fourier series as they converge to -gons. The vertices remain slightly rounded as a result of the Gibbs phenomenon.[more]
A regular self-intersecting star polygon is created by connecting one vertex of a regular -sided polygon to a nonadjacent vertex and continuing until the path returns to the original vertex; this process would need to be repeated if , but such pairs are avoided here.[less]
 F. A. Farris, Creating Symmetry, The Artful Mathematics of Wallpaper Patterns, Princeton: Princeton University Press, 2015 p. 30.