Show that a map T:R2→R2 is an isometry for the Euclidean metric on the plane R2 if and only if there is a vector v∈R2 and an orthogonal linear map B∈O(2) with
T(x)=B(x)+v for all x∈R2
When T is an isometry with detB=−1, show that T is either a reflection or a glide reflection.