Answer: SSS
Explanation:
SSS congruence postulate: If all the three sides of one triangle are equivalent to the corresponding three sides of the another triangle, then the two triangles are congruent.
In the given figure, we have
ΔPQR and ΔPQS such that
PQ = PQ [common]
PR= PS [Given]
RQ = QS [Given]
By SSS congruence postulate,
ΔPQR ≅ΔPQS
So, the right choice : "SSS"