I'm not a skilled user too . For the surface of a quadrilateral (a slightly twisted room) ABCD, I use these formulas :
2S = abs((xA-xC)*(yB-yD)) + abs((xB-xD)*(yA-yC)) Where xM,yM are the coordinate off M point...
I need to copy manually each coordinate > Excel :( Is there a function for this ?
Or 2S = D * (H1 + H2) Where D is the diagonal BD and Hx the heights on D of A and C
I need to create 3 new lines and > Excel ...
If a programmer can look into :)
Sorry for my poor English