In ΔBPC and ΔAPD, it is known that the vertically opposite angles are equal, so,
∠BPC=∠APD
∠APD=124∘
In ΔAPD, the opposite angles are equal,
∠DAP=∠ADP
∠DAP+∠ADP+∠APD=180∘
∠ADP+∠ADP=180∘−124∘
∠ADP=28∘
In rectangle ABCD,
∠DAB=∠DAP+∠PAB
90∘=28∘+∠PAB
∠PAB=62∘