The figure below shows segments pq and rs which intersect at point t. segment pr is parallel to segment sq.

which of these facts is used to prove that triangle ptr is similar to triangle qts

line segment rt is congruent to line segment ts because corresponding parts of congruent triangles are congruent.

line segment pr is congruent to line segment sq because parallel segments are congruent.

angle ptr is congruent to angle qts because they are vertical angles.

angle prt is congruent to angle qst because they are vertical angles.