How to check the angle and undercuts?

Hello, this is Lee.

I'm learning to make a plastic mold and injection.

But before going to cavity process, on the way to make product model, I actually couldn't find how to check the angles from core line(Red line on the image) and undercuts(Blue area on the image)

When I handle complicated designs like this, It is hard to check those every problem manually.

I've seen before someone checking those problems for injection mold automatically.

I also attached the modeling file below.

I need your help, smart guys.

Best regards :-)

SolidworksPlastics And Mold Design