In the diagram, PQRS is a cyclic quadrilateral. ST is a tangent to the circle at S and chord SR is produced to V. PQ = QR, ∠S_{1} = 42° and ∠S_{2} = 108°.
Determine with reasons, the size of the following angles

8.1∠Q(2)

8.2∠R_{2}(2)

8.3∠P_{2}(2)

8.4∠R_{3}(2)
(8)
[{"prnt":"8","num":"8.1","answer":""},{"prnt":"8","num":"8.2","answer":""},{"prnt":"8","num":"8.3","answer":""},{"prnt":"8","num":"8.4","answer":""}]