From the given information, you can deduce that triangle QTR is equilateral and equiangular (all angles are 60 degrees)
b, c, d, and f are true
The opposite angles of a parallelogram are congruent (b)
If 2 parallel lines are cut by a transversal, then the corresponding angles are congruent (d)
Angle RQT is congruent to angle QRT, and angle QRT is congruent to angle S. By the transitive property, angle RQT is congruent to angle S (c)
Transitive property, like c (f)