Does a rectangle have reflectional symmetry?

Yes, rectangle has reflectional symmetry. Just identify the center of gravity of your rectangle or literally, the center axis. Draw a straight line from any direction and you can have your rectangle split into two. The resulting areas will be similar. In terms of rotational symmetry, imagine that you put a stick ping through again the center axis, make your rectangle spin and you can make a symmetrical prism out of it.