So, the ones that are on the inside of the shapes are angles, and the lines are sides. What you’ll do is, you’ll read them as: side angle side(SAS) or, side side side(SSS). So for example problem 3 would be side angle side(SAS), because there is one angle in the middle and two sides on the out side. If you read one as angle angle side(AAS) or side side angle(SSA) or angle side angle(ASA) you’ll put not congruent. I hope this helps.