Polygon names and miscellaneous properties

Polygon names and miscellaneous properties

Name	Sides	Properties
monogon	1	Not generally recognised as a polygon,[18] although some disciplines such as graph theory sometimes use the term.[19]
digon	2	Not generally recognised as a polygon in the Euclidean plane, although it can exist as a spherical polygon.[20]
triangle (or trigon)	3	The simplest polygon which can exist in the Euclidean plane. Can tile the plane.
quadrilateral (or tetragon)	4	The simplest polygon which can cross itself; the simplest polygon which can be concave; the simplest polygon which can be non-cyclic. Can tile the plane.
pentagon	5	[21] The simplest polygon which can exist as a regular star. A star pentagon is known as a pentagram or pentacle.
hexagon	6	[21] Can tile the plane.
heptagon (or septagon)	7	[21] The simplest polygon such that the regular form is not constructible with compass and straightedge. However, it can be constructed using a neusis construction.
octagon	8	[21]
nonagon (or enneagon)	9	[21]"Nonagon" mixes Latin [novem = 9] with Greek; "enneagon" is pure Greek.
decagon	10	[21]
hendecagon (or undecagon)	11	[21] The simplest polygon such that the regular form cannot be constructed with compass, straightedge, and angle trisector. However, it can be constructed with neusis.[22]
dodecagon (or duodecagon)	12	[21]
tridecagon (or triskaidecagon)	13	[21]
tetradecagon (or tetrakaidecagon)	14	[21]
pentadecagon (or pentakaidecagon)	15	[21]
hexadecagon (or hexakaidecagon)	16	[21]
heptadecagon (or heptakaidecagon)	17	Constructible polygon[17]
octadecagon (or octakaidecagon)	18	[21]
enneadecagon (or enneakaidecagon)	19	[21]
icosagon	20	[21]
icositrigon (or icosikaitrigon)	23	The simplest polygon such that the regular form cannot be constructed with neusis.[23][22]
icositetragon (or icosikaitetragon)	24	[21]
icosipentagon (or icosikaipentagon)	25	The simplest polygon such that it is not known if the regular form can be constructed with neusis or not.[23][22]
triacontagon	30	[21]
tetracontagon (or tessaracontagon)	40	[21][24]
pentacontagon (or pentecontagon)	50	[21][24]
hexacontagon (or hexecontagon)	60	[21][24]
heptacontagon (or hebdomecontagon)	70	[21][24]
octacontagon (or ogdoëcontagon)	80	[21][24]
enneacontagon (or enenecontagon)	90	[21][24]
hectogon (or hecatontagon)[25]	100	[21]
257-gon	257	Constructible polygon[17]
chiliagon	1000	Philosophers including René Descartes,[26] Immanuel Kant,[27] David Hume,[28] have used the chiliagon as an example in discussions.
myriagon	10,000	Used as an example in some philosophical discussions, for example in Descartes's Meditations on First Philosophy
65537-gon	65,537	Constructible polygon[17]
megagon[29][30][31]	1,000,000	As with René Descartes's example of the chiliagon, the million-sided polygon has been used as an illustration of a well-defined concept that cannot be visualised.[32][33][34][35][36][37][38] The megagon is also used as an illustration of the convergence of regular polygons to a circle.[39]
apeirogon	∞	A degenerate polygon of infinitely many sides.