Editing Reflection symmetry (section)

==Symmetric geometrical shapes==
{| class="wikitable floatright" align=right
|+ 2D shapes w/reflective symmetry
|[[File:Isosceles_trapezoid.svg|100px]]
|[[File:GeometricKite.svg|100px]]
|-
!colspan=2|[[isosceles trapezoid]] and [[kite (geometry)|kite]]
|-
|[[File:Hexagon p2 symmetry.png|100px]]
|[[File:Hexagon d3 symmetry.png|100px]]
|-
!colspan=2|[[Hexagon]]s
|-
|[[File:Octagon p2 symmetry.png|100px]]
|[[File:Octagon d2 symmetry.png|100px]]
|-
!colspan=2|[[octagon]]s
|}

[[Triangle]]s with reflection symmetry are [[isosceles]]. [[Quadrilateral]]s with reflection symmetry are [[kite (geometry)|kite]]s, (concave) deltoids, [[rhombi]],<ref>{{cite book |last1=Gullberg |first1=Jan |author-link=Jan Gullberg |title=Mathematics: From the Birth of Numbers |url=https://archive.org/details/mathematicsfromb1997gull |url-access=registration |date=1997 |publisher=W. W. Norton |isbn=0-393-04002-X|pages=[https://archive.org/details/mathematicsfromb1997gull/page/394 394–395]}}</ref> and [[isosceles trapezoid]]s. All even-sided polygons have two simple reflective forms, one with lines of reflections through vertices, and one through edges. For an arbitrary shape, the [[axiality (geometry)|axiality]] of the shape measures how close it is to being bilaterally symmetric. It equals 1 for shapes with reflection symmetry, and between two-thirds and 1 for any [[Convex polygon|convex shape]].

In 3D, the cube in which the plane can configure in all of the three axes that can reflect the cube has 9 planes of reflective symmetry.<ref>{{Cite journal |last=O’Brien |first=David |last2=McShane |first2=Pauric |last3=Thornton |first3=Sean |title=The Group of Symmetries of the Cube |url=https://maths.nuigalway.ie/~rquinlan/groups/exhibition/mcshane_obrien_thornton.pdf |journal=NUI Galway}}</ref>