Consider the isosceles triangle \(PQR\) with \(PQ = PR\) and \(PS\) is the bisector of \(∠QPR\) whose interior angle is 108\(°\). Find the required corresponding vertex, angle and parts.
1. The correspondence of vertex \(S\) in triangle \(PQS\) to the triangle \(PRS\) is .
2. The \(∠QPS\) of triangle \(PQS\) corresponds to \(∠\) of triangle \(PSR\).
3. The equal pair of side \(QS\) is .
4. The included angles \(QPS\) and \(SPR\) measure \(°\).