The view you are wanting to generate is not a true 3D view...
Say you draw a cube and rotate it 30° clockwise, viewing from above. The front side is now at 30° with respect to the X axis, while the right side is 60° (the corner of the cube is 90°, so when you add them up they total 180°).
Now, if you rotate the cube about the X axis, such that you can see the verticals of the cube, the appearance of the front bottom edge to the X axis becomes less than 30°, while the right bottom edge appears as less than 60°. If you continue to rotate in this manner a full 90°, those bottom edges will appear to be 0°.