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°.

Maumbo mbalimbali za pembenne

 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  at Dynamic Math Learning Homepage 
 The role and function of a hierarchical classification of quadrilaterals  by Michael de Villiers

Jamii:Jiometria