Definition:Dihedral Group

Definition
The dihedral group $D_n$ of order $2 n$ is the group of symmetries of the regular $n$-gon.

Even Polygon

 * SymmetryGroupEvenPolygon.png

Odd Polygon

 * SymmetryGroupOddPolygon.png

Also see

 * Dihedral Group is Group


 * Dihedral Group as Semidirect Product where it is shown that $D_n$ can be defined as the semidirect product $\Z_n \rtimes \Z_2$.