Cyclic group of order four
= Cyclic group of order four
{title2=$C_4=\mathbb Z/4\mathbb Z$}
The <cyclic group> generated by $r$ with $r^4=e$ and $r^2\ne e$ has elements $e,r,r^2,r^3$. It is realized by quarter-turn <rotations> of a plane. The <cyclic group of order four and Klein four-group> have the same order but different element orders: the latter has no element of order four.