This is a list of two-dimensional geometric shapes in Euclidean and other geometries. For mathematical objects in more dimensions, see list of mathematical shapes. For a broader scope, see list of shapes.
Generally composed of straight line segments
Angle Balbis Concave polygon Constructible polygon Convex polygon Cyclic polygon Equiangular polygon Equilateral polygon Penrose tile Polyform Regular polygon Simple polygon Tangential polygon
Polygons with specific numbers of sides Monogon - 1 side Digon/Bigon - 2 sides Triangle – 3 sides Acute triangle Equilateral triangle Heptagonal triangle Isosceles triangle Golden Triangle Obtuse triangle Rational triangle Heronian triangle Pythagorean triangle Isosceles heronian triangle Primitive Heronian triangle Right triangle 30-60-90 triangle Isosceles right triangle Kepler triangle Scalene triangle Quadrilateral – 4 sides Cyclic quadrilateral Kite Rectangle Rhomboid Rhombus Square (regular quadrilateral) Tangential quadrilateral Trapezoid Isosceles trapezoid Pentagon – 5 sides Hexagon – 6 sides Lemoine hexagon Heptagon/Septagon – 7 sides Octagon – 8 sides Nonagon/Enneagon – 9 sides Decagon – 10 sides Hendecagon – 11 sides Dodecagon – 12 sides Tridecagon – 13 sides Tetradecagon – 14 sides Pentadecagon – 15 sides Hexadecagon – 16 sides Heptadecagon – 17 sides Octadecagon – 18 sides Enneadecagon – 19 sides Icosagon – 20 sides Icosikaihenagon - 21 sides Icosikaidigon - 22 sides Icositrigon - 23 sides Icositetragon - 24 sides Icosikaipentagon - 25 sides Icosikaihexagon - 26 sides Icosikaiheptagon - 27 sides Icosikaioctagon - 28 sides Icosikaienneagon - 29 sides Triacontagon - 30 sides Tetracontagon - 40 sides Tetracontakaienneagon 49 sides Pentacontagon - 50 sides Hexacontagon - 60 sides Heptacontagon - 70 sides Heptacontapentagon - 75 sides Octacontagon - 80 sides Enneacontagon - 90 sides Hectogon - 100 sides Dihectogon - 200 sides Trihectogon - 300 sides Tetrahectogon - 400 sides Pentahectogon - 500 sides Hexahectogon - 600 sides Heptahectogon - 700 sides Octahectogon - 800 sides Enneahectogon - 900 sides Chiliagon - 1,000 sides Dischiliagon - 2,000 sides Trischiliagon - 3,000 sides Nonanonacontanonactanonaliagon - 9,999 sides Myriagon - 10,000 sides Megagon - 1,000,000 sides Cross - 12 sides Star polygon – there are multiple types of stars Pentagram - star polygon with 5 sides Hexagram – star polygon with 6 sides Star of David (example) Heptagram – star polygon with 7 sides Octagram – star polygon with 8 sides Star of Lakshmi (example) Enneagram - star polygon with 9 sides Decagram - star polygon with 10 sides Hendecagram - star polygon with 11 sides Dodecagram - star polygon with 12 sides Apeirogon - generalized polygon with countably infinite set of sides
Curved
Composed of circular arcs Annulus Arbelos Circle Archimedes' twin circles Bankoff circle Circular triangle Reuleaux triangle Circumcircle Disc Incircle and excircles of a triangle Nine-point circle Circular sector Circular segment Crescent Heart Lens, vesica piscis (fish bladder) Lune Quatrefoil Reuleaux polygon Reuleaux triangle Salinon Semicircle Stadium Tomahawk Trefoil Triquetra
Not composed of circular arcs Archimedean spiral Astroid Cardioid Deltoid Ellipse Various lemniscates Nephroid Oval Cartesian oval Cassini oval Oval of Booth Superellipse Taijitu Tomoe Magatama
See also List of triangle topics List of circle topics Glossary of shapes with metaphorical names
References