Given PQ = QR and angle Q1 = x, calculate angle P1 in terms of x, with reasons.

Here's the solution to Q2:

Given:

1. O is the center of the circle.
2. P, Q, R, S are points on the circumference.
3. TOQ is a straight line (T, O, Q are collinear).
4. T lies on PS.
5. $PQ = QR$.
6. $\angle Q_1 = x$. ($\angle PQS = x$)

2.1 Calculate with reasons, $\angle P_1$ in terms of $x$.

Step 1: Identify equal angles due to equal chords.
Since $PQ = QR$ (given), the chords are equal. Equal chords subtend