Pembenne : Tofauti kati ya masahihisho

 

== Viungo vya nje ==

*[http://www.vias.org/comp_geometry/geom_quad_general.html Compendium Geometry] Analytic Geometry of Quadrilaterals

*[http://www.cut-the-knot.org/Curriculum/Geometry/PerpBisectQuadri.shtml Quadrilaterals Formed by Perpendicular Bisectors], [http://www.cut-the-knot.org/Curriculum/Geometry/ProjectiveQuadri.shtml Projective Collinearity] and [http://www.cut-the-knot.org/Curriculum/Geometry/Quadrilaterals.shtml Interactive Classification] of Quadrilaterals from [[cut-the-knot]]