From the question, we know that we will be looking at <3, <4, and angles TKL and TLK. That being said, since <3 is congruent to <4, that means that angles TKL and TLK, which are each supplementary to either angle 3 or 4, are congruent because, since angles 3 and 4 are congruent, they are congruent because the supplements of congruent angles are congruent.
