Answer: ASA
Reasoning:
Although it appears the two triangles only contain a pair of corresponding, congruent angles and an included pair of corresponding, congruent sides, there is one more angle pair. Angles STR and UTV are vertical angles, making them congruent. Therefore, we know have a pair of corresponding, congruent angels, a pair of the included corresponding, congruent sides, and another pair of corresponding, congruent angles. Thus, ASA can be used.