Given the base of pyramid P-ABCD is a square, PA⊥ Base ABCD , ∠PDA=45° . E , F are the midpoints of edge AB and PD, respectively. Prove

(1) AF∥ Plane PCE

(2) Plane PCE⊥ Plane PCD

Given the base of pyramid P-ABCD is a square, PA⊥ Base ABCD , ∠PDA=45° . E , F are the midpoints of edge AB and PD, respectively. Prove

(1) AF∥ Plane PCE

(2) Plane PCE⊥ Plane PCD