Pls answer

Q. In the given figure, a cyclic quadrilateral PQRS is shown and an isosceles triangle PST with PT = TS is shown.
The line RST is a stright line. Also, PQ = QS 
If $\angle$PST = 72° and $\angle$PSQ = 56°, then find :

   (a) $\angle$PST (2 marks)
   (b) $\angle$POS (2 marks)
   (d) $\angle$POS (2 marks )
   (d) $\angle$PRS (2 marks)