A park has a triangular warning sign with angles measuring \(90^{\circ}\), \(83^{\circ}\), and \(7^{\circ}\).
1. Classify the triangle based on its angles.
2. Which angle makes this classification possible?
3. If the vertices are named \(P\), \(Q\) and \(R\), then the angles are
4. If the sides of the triangle measure \(4 \ m\), \(8 \ m\) and \(11 \ m\), then it is