Hi skipper, so do you mean you want to rotate 2 split halves similar to this? :





But won't that introduce a cusp in your profile at the rotation point here? :



Or ok I guess now that I read your question again it sounds like you are going to rotate only half the control points and not a cut apart piece.

So I guess what you would do would be to offset the centerline by half your desired thickness:




Then your end location would be the intersection of a circle with origin at your rotation origin and going through your endpoint, with the offset line:








The rotate command does internally create such a circle automatically and provides an intersection snap point so you can skip making the circle and only make the offset line.

Does that do what you need?

- Michael