Hello - I see, I thought from your images the problem was a different one. I think there is a more exact process to get the answer you want but right now it escapes me if it exists. I’ve made a quick script that should get you a very good estimate - it is fairly crude and does not do any checking for coplanarity, if that is a word, but it should work for the case you show and similar.
MoveToTangent.py (1.9 KB)
To use the Python script use
RunPythonScript, or a macro:
_-RunPythonScript "Full path to py file inside double-quotes"