Ok so it looks like the new question is:
Which tool can create new n-gons from quads or triangles?
Bevel
Inset
Extrude
Loop Cut
My answer would have been the Knife tool but unfortuanately that wasn't an option. Jonathan seems correct when he says "I don't think extrude or inset will ever make new n-gons that weren't there before". Since the Loop Cut tool won't cut through a triangle, that leaves only the Bevel tool. Now if I add a cube (quad) to my viewport and bevel it, triangles appear in the corners. Is this an example of what the question is asking? If not, could someone provide a good example. Thanks!
You can also get triangles from the bevel tool, but when it comes to n-gons, it's quite common when beveling a single edge:
I believe the bevel tool video is the only one out of the options that warns about creating n-gons, so the question should match up with the lessons.