RS Bisects QT means, it cuts QT in two equal halves, so QP would be equal to PT, as it is an isosceles triangle, one other side would be equal as well, so RP is equal to PS, Now, by ASA, we conclude the both mentioned triangles in the figure are congruent.
Hope this helps!
Chang has a 50% probability of getting the white shirt and tan pants
9(3b-2) Iv factorised it but I dont know the rest sorry
