(Watching TV now, will respond soon).
@RTCool, my earlier remark was just a copy of what I wrote in a response to @mihai.s where he showed two angles 90 degrees. Hobby mihai.s - #113 by mihai.s
Your method is correct if its about creating a vertical connecting edge.
I was thinking along the “line” of creating the shortes connecting edge between two arbitrary lines.
I hope OP will be back to explain what the real question is.
- intersection (my answer above which might be missing the point entirely)
- drap (in horizontal edges case, as shown by @mihai.s) and what you showed
- the shortest connecting edge (in all arbitrary situations)