Summer exercice

 From:  Frenchy Pilou (PILOU)
9901.37 In reply to 9901.36 
These segments can be many things!
Normal to the center of losange then move in their 4 places for intersection with the future growing plane from the losange
Vertical Z...
Inclined to a groundbase for be aligned at something...
etc...
all this will give slightly different results for your Plane following that you want ...