So we should start by marking all of the information that we already know. So we mark line JK and line LM congruent and parallel to each other. Since these lines are parallel to each other line JK can be considered the transversal of JK and LM. Know we can use the alternate angle theorem to say that angle KLM is congruent to angle JKL. Therefore you can prove the two triangles congruent by using the theorem SAS or C.