The floor object is now ready to be incorporated into the full scene. Using layer scaling and perspective tools the floor is adjusted until the lines of the tiles match more-or-less with the shelf bottoms. Obviously the perspective is not going to be perfect, so as long as the floor angle looks convincing enough, we're alright.
Note: When using the perspective tools (or any tool, for that matter), remember to experiment. See what happens when the CTRL, ALT or SHIFT keys are held down when using a tool. Sometimes even combining two or three of the keys will have a different, useful effect.