Here's the solution to question 3:
a) Prove that PT∥QS
Step 1: Identify given parallel lines and angles.
We are given that PU∥QT.
We are given the following angles:
∠UPT=x
∠QPT=x+40∘
∠PQT=y
∠QTS=42∘
∠RQS=82∘
Step 2: Use properties of parallel lines PU∥QT.
Since PU∥QT and PT is a transversal, the alternate interior angles are equal:
∠UPT=∠PTQ