Editing Regular polygon (section)

====Interior points====
For a regular {{mvar|n}}-gon, the sum of the perpendicular distances from any interior point to the {{mvar|n}} sides is {{mvar|n}} times the [[apothem]]<ref name=Johnson>Johnson, Roger A., ''Advanced Euclidean Geometry'', Dover Publ., 2007 (orig. 1929).</ref>{{rp|p. 72}} (the apothem being the distance from the center to any side). This is a generalization of [[Viviani's theorem]] for the ''n'' = 3 case.<ref>Pickover, Clifford A, ''The Math Book'', Sterling, 2009: p. 150</ref><ref>Chen, Zhibo, and Liang, Tian. "The converse of Viviani's theorem", ''[[The College Mathematics Journal]]'' 37(5), 2006, pp. 390–391.</ref>