Wings as a math visualization tool...

[Dimitri]

Yes, now it is ok Micheus... with your new visual demonstration it is clearly evident that you got the question. And, also, it seems you did find the way to the answer. I am not so sure yet however, I have to inspect the logic you followed... but it seems that it is working, indeed. Happy to see that. I will think on it. : - )

It is true that I do like geometry problems but the main reason I made this post was not for finding a solution to the presented problem... it was mainly for putting forth the abilities that 3D modelling offers for their presentation (as is so evident from your visuals too... they are very cleverly conceived, really).

Thank you for your so inspired effort...

(btw, not 'quadrangles' but 'squares': my so poor English... : - )