missing something else?

The upper level and the lower level both have a rectangular floor plan, with one dimension greater than the other. The two longer dimensions are at right angles to each other in the horizontal plane. Therefore, if the left front corners are aligned vertically, the right rear corners will not be and vice versa.


 ---Y
|   |
|   |
|   |
|   |
 ----------Y
|          |
 X----------