Chapter 4 - Congruent Triangles - 4-2 Triangle Congruence by SSS and SAS - Practice and Problem-Solving Exercises - Page 231: 11

You would need to prove that GL is congruent to MQ.

In order to use the SAS postulate, you must prove that two different sets of sides are congruent. Then, you must show that the angle joining those two sides is congruent for the two triangles as well. Thus, you need to prove that one more side is congruent.