#### Question

Given the base of pyramid P-ABCD is a square. If the side of the square is 1 in length , PA\perp CD , PA=1 , PD=\sqrt{2} .

Prove PA\perp plabe ABCD

Given the base of pyramid P-ABCD is a square. If the side of the square is 1 in length , PA\perp CD , PA=1 , PD=\sqrt{2} .

Prove PA\perp plabe ABCD