# are isometries on euclidean plane translations

Let $m$ be an isometry in euclidean plane that changes orientation. Prove that $m \circ m$ is a translation.I do not have an idea how to start the proof of this exercise.

• A good way to start is to find all orientation reversing isometries. – Amitai Yuval Dec 12 '14 at 20:22
• I'm sorry, what is $m*2$? – Jorge Fernández Hidalgo Dec 12 '14 at 20:54
• It is m to power 2 – mathstudent Dec 12 '14 at 21:07