Find inside acute corners using API

I have a challenge that I want to automate using the API. I need to find all inside corners that cannot be machined. Those inside corners need to be filleted. We can fillet them manually, I just want to find them at this point.

We are currently looking over models but when they get complex it gets easy to overlook a corner that cannot be machined. My initial thought is to look for surfaces or faces that have less than 180 degree angles between them. This might work for planar faces but not all of my faces will be planar. It also seems that I would need to know the inside of my solid so I can tell the "sense" of the angle.

Is there anybody with some experience out there that could point me in the right direction regarding this?

SolidworksApi/macros