Just curious, how would you constrain this and why.

Would you select the edge of the Boss or use Convert Entities first and constrain to that result?

Or would you draw a construction line that is co-linear with the edge and constrain tot hat?

Is it possible to constrain the sketch line to the face rather than the edge?

Sorry if this seems very trivial to you.

I'm trying to get back to basics and understand which approach is most stable.