∠PBA=∠ABC−∠PBC=90°−60°=30° Further in ΔABP PB=AB=a⇒∠BPA=∠BAP Further 2(∠BPA)+∠PBA=180° ⇒ 2∠BPA=180°−30°=150° ⇒ ∠BPA=75°=∠BAP Similarly ∠PAD=90°−∠PAB=90°−75°=15° Again in right angled ΔAPE, ∠EPA=90°−∠PAE=90°−15°=75° Similarly we can calculate that ∠DPE=75° ∴ ∠DPA=75°+75°=150°