1. In the given figure, \(AD = CD\) and \(AB = CB\). Identify the other three pairs that are equal.

2. In \(\Delta ABC\) and \(\Delta PQR\), \(\angle A = 50^\circ = \angle P\), \(PQ = AB\) and \(PR = AC\). By which property \(\Delta ABC\) and \(\Delta PQR\) are congruent?