Which fact is not used to prove that pqr is similar to str? segments st and pq are parallel. angle p is congruent to itself due to the reflexive property. rp is a transversal line passing st and pq. angles rts and rqp are congruent due to the corresponding angles postulate.

The fact that is not used to prove that PQR is similar to STR is that "Angle P is congruent to itself due to the reflexive property." The statements Segments ST and PQ are parallel, RP is a transversal line passing ST and PQ and Angles RTS and RQP are congruent due to the Corresponding Angles Postulate are all true.