Editing Quadrilateral (section)

===Properties of the diagonals in quadrilaterals===
In the following table it is listed if the diagonals in some of the most basic quadrilaterals bisect each other, if their diagonals are [[perpendicular]], and if their diagonals have [[congruence (geometry)|equal length]].<ref>{{Cite web|url=https://math.okstate.edu/geoset/Projects/Ideas/QuadDiags.htm|title=Diagonals of Quadrilaterals -- Perpendicular, Bisecting or Both|website=Math.okstate.edu|access-date=1 March 2022}}</ref> The list applies to the most general cases, and excludes named subsets.

{| class="wikitable"
|-
! scope="col" | Quadrilateral
! scope="col" | Bisecting diagonals
! scope="col" | Perpendicular diagonals
! scope="col" | Equal diagonals
|-
! scope="row" | [[Trapezoid]] 
| {{No}} || ''See note 1'' || {{No}}
|-
! scope="row" | [[Isosceles trapezoid]] 
| {{No}} || ''See note 1'' || {{Yes}}
|-<!--
! scope="row" | [[Right trapezoid]]
|| ''See note 3'' || ''See note 1'' || {{No}}
|--->
! scope="row" | [[Parallelogram]] 
| {{Yes}} || {{No}} || {{No}}
|-
! scope="row" | [[Kite (geometry)|Kite]] 
| ''See note 2'' || {{Yes}} || ''See note 2''
|-
! scope="row" | [[Rectangle]] 
| {{Yes}} || {{No}} || {{Yes}}
|-
! scope="row" | [[Rhombus]] 
| {{Yes}} || {{Yes}} || {{No}}
|-
! scope="row" | [[Square]] 
| {{Yes}} || {{Yes}} || {{Yes}}
|}

* ''Note 1: The most general trapezoids and isosceles trapezoids do not have perpendicular diagonals, but there are infinite numbers of (non-similar) trapezoids and isosceles trapezoids that do have perpendicular diagonals and are not any other named quadrilateral.''
* ''Note 2: In a kite, one diagonal bisects the other.  The most general kite has unequal diagonals, but there is an infinite number of (non-similar) kites in which the diagonals are equal in length (and the kites are not any other named quadrilateral).''