I have two similar sheet metal parts that are exactly the same expect one has a flange bent at 90 degrees and the other at 86 degrees.  These flanges have the same size slots in them and the slots are cut perpendicular to the flange face.  In the drawing of the flattened pattern, I can add the center mark for the slots in the part that has the 90 degree bend, but I am unable to do this to the part with the 86 degree bend.  Has anyone come across this problem and found a solution to it?