parallelogram door

Arthur Lee
Click this link to see a parallelogram door. In the following applet, the green door is rectangular. Notice the movement of D when you open the door by dragging D.  Drag B to the right of the vertical white line to make the door a parallelogram. Imagine movement of D again and try opening the door. Can the door be tilted to the left in the real building?
Here is an example of open parallelogram window.