In geometry, a pentagon (frae pente, which is Greek for the nummer 5) is ony five-sidit polygon. A pentagon mey be simple or self-intersectin. The sum o the internal angles in a simple pentagon is 540°. A pentagram is an example o a self-intersectin pentagon.

Regular pentagon
Regular polygon 5 annotated.svg
A regular pentagon
TeepRegular polygon
Edges an vertices5
Schläfli seembol{5}
Coxeter diagramCDel node 1.pngCDel 5.pngCDel node.png
Symmetry groupDihedral (D5), order 2×5
Internal angle (degrees)108°
Dual polygonSel
PropertiesConvex, cyclic, equilateral, isogonal, isotoxal