Regular Polygon

An $n$-sided Polygon in which the sides are all the same length and are symmetrically placed about a common center. The sum of Perpendiculars from any point to the sides of a regular polygon of $n$ sides is $n$ times the Apothem. Only certain regular polygons are ``Constructible'' with Ruler and Straightedge.

$n$	Regular Polygon
3	Triangle
4	Square
5	Pentagon
6	Hexagon
7	Heptagon
8	Octagon
9	Nonagon
10	Decagon
12	Dodecagon
15	Pentadecagon
16	Hexadecagon
17	Heptadecagon
18	Octadecagon
20	Icosagon
30	Triacontagon

See also Constructible Polygon, Geometrography, Heptadecagon, Polygon

References

Bishop, W. ``How to Construct a Regular Polygon.'' Amer. Math. Monthly 85, 186-188, 1978.