List of two-dimensional geometric shapes
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
- 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
- * Tangential quadrilateral
- * Trapezoid
- ** Isosceles trapezoid
- * Trapezus
- Pentagon – 5 sides
- Hexagon – 6 sides
- * Lemoine hexagon
- Heptagon – 7 sides
- Octagon – 8 sides
- Nonagon – 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
- – 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
- Myriagon - 10,000 sides
- Megagon - 1,000,000 sides
- Star polygon – there are multiple types of stars
- * Pentagram - star polygon with 5 sides
- * Hexagram – star polygon with 6 sides
- ** Star of David
- * Heptagram – star polygon with 7 sides
- * Octagram – star polygon with 8 sides
- ** Star of Lakshmi
- * 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
- Lens, vesica piscis
- Lune
- Quatrefoil
- Reuleaux polygon
- * Reuleaux triangle
- Salinon
- Semicircle
- Stadium
- Tomahawk
- Trefoil
- Triquetra