Pembenne

Pembenne ni umbo bapa lenye pande nne. Kwa lugha nyingine ni pembenyingi yenye pembe nne.

Pembenne hutokea kama nukta nne kwenye ubapa zinaunganishwa kwa mistari inayofunga eneo ndani yake.

Maumbo ya pekee ya pembenne ni mstatili, mraba, trapeza na msambamba.

Kila pembenne huwa na ulalo mbili.

Jumla ya pembe zote ndani ya pembenne ni nyuzi 360°.

Viungo vya nje

• Compendium Geometry Analytic Geometry of Quadrilaterals
• Quadrilaterals Formed by Perpendicular Bisectors, Projective Collinearity and Interactive Classification of Quadrilaterals from cut-the-knot
• Definitions and examples of quadrilaterals and Definition and properties of tetragons from Mathopenref
• An extended classification of quadrilaterals Archived 30 Desemba 2019 at the Wayback Machine. at Dynamic Math Learning Homepage Archived 25 Agosti 2018 at the Wayback Machine.
• The role and function of a hierarchical classification of quadrilaterals Archived 19 Julai 2011 at the Wayback Machine. by Michael de Villiers