1. If \(PQR\) is a triangle of sides \(PQ\) \(=\) 10 \(cm\), \(QR\) \(=\) 11 \(cm\) and perimeter \(=\) 30 \(cm\), then \(RS\) \(=\) \(cm\).
2. If \(PQR\) is a triangle of sides \(PQ\) \(=\) 43 \(cm\), \(RS\) \(=\) 45 \(cm\) and perimeter \(=\) 134 \(cm\), then \(QR\) \(=\) \(cm\).