Chapter 4 - Congruent Triangles - 4-2 Triangle Congruence by SSS and SAS - Practice and Problem-Solving Exercises - Page 232: 24

$SAS$ postulate

For this problem, $\overline{AN}$ is congruent to $\overline{RW}$, $\overline{NG}$ is congruent to $\overline{WT}$, and $\angle N$ is congruent to $\angle W$. We have two sides congruent to one another plus the angle between them. Therefore, we can use the $SAS$ postulate to prove that these triangles are congruent.