List of two-dimensional geometric shapes
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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
=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 (regular quadrilateral)
- 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
- 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
- Pentacontagon - 50 sides
- Hexacontagon - 60 sides
- Heptacontagon - 70 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
- 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 (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
{{main|List of curves}}
=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 (fish bladder)
- Lune
- Quatrefoil
- Reuleaux polygon
- Reuleaux triangle
- Salinon
- Semicircle
- Tomahawk
- Trefoil
- Triquetra