Mirroring across the two non-principal planes

To mirror an object across the two non-principal planes:

1. Select the object to mirror.
2. Click Edit tab > Transform panel > Mirror.
3. Click Create multiple copies of the same item on the Mirror toolbar.

   The object is copied three times and mirrored across the two non-principal planes.

   A preview of the copied objects, together with the mirror planes, is displayed:

   

4. Click Apply to accept the changes or Cancel .