Let X be a subset of the Euclidean plane. Let GX be the set
of isometries of the plane that leave X invariant, i.e.
GX = {f : f is isometry and f(X) = X}
Show that GX is a group of transformations. (Elements of GX are sometimes
called ”symmetries of X in the plane”.)
of isometries of the plane that leave X invariant, i.e.
GX = {f : f is isometry and f(X) = X}
Show that GX is a group of transformations. (Elements of GX are sometimes
called ”symmetries of X in the plane”.)