triangle
trilateral
trigon
equilateral triangle
equiangular triangle
quadrilateral
quadrangle
tetragon
nonagon
dodecagon
hexagon
heptagon
fourgon
undecagon
octagon
pentagon
many-sided
poly
polygonal
hectogon
enneagon
polyangle
pentacontagon
hexacontagon
tessellation
heptacontagon
tetracontagon
three-cornered
icositrigon
decagon
hexahectaenneacontakaiheptagon
tetradecagon
tetrakaidecagon
enneacontahexagon
polygonically
polygonic
polygonial
tetracontakaihexagon
polygonate
polygonar
polygonous
triacontatetragon
enneacontagon
triacontakaitetragon
regularity
excircle
digon
geometrical regularity
bigon
exterior angle