9514 1404 393
Answer:
SAS
Step-by-step explanation:
Count the number of sides marked congruent. One is marked with a single hash mark, and one is marked with a double hash mark, for a total of two.
That means the chosen congruence theorem will have S appear twice in its name, excluding AAS, ASA, and SSS.
We also note that the angles between the marked sides are vertical angles, hence congruent. The theorem that depends on two sides (SS) and the angle between them (_A_) is the SAS theorem.