Difference between revisions of "Dihedral group"

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* The [[order (group theory)|order]] of <math>D_{2n}</math> is <math>2n</math>.
 
* The [[order (group theory)|order]] of <math>D_{2n}</math> is <math>2n</math>.
* The group <math>D_{2n}</math> has a [[presentation]] in the form <math><r, s|r^n = 1, s^2 = 1, srs = r^{-1}></math>.
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* The group <math>D_{2n}</math> has a [[presentation]] in the form <math>\langle r, s\mid r^n = 1, s^2 = 1, srs = r^{-1}\rangle</math>.
 
* For <math>n > 3</math>, <math>D_{2n}</math> is noncommutative.
 
* For <math>n > 3</math>, <math>D_{2n}</math> is noncommutative.
  

Latest revision as of 09:17, 11 March 2024

The dihedral groups $D_{2n}$ are an infinite family of groups which are in general noncommutative. Each dihedral group $D_{2n}$ is defined to be the group of linear symmetries of a regular $n$-gon.

Properties

  • The order of $D_{2n}$ is $2n$.
  • The group $D_{2n}$ has a presentation in the form $\langle r, s\mid r^n = 1, s^2 = 1, srs = r^{-1}\rangle$.
  • For $n > 3$, $D_{2n}$ is noncommutative.

See also