#### Question

Given pyramid P-ABCD , its base ABCD is a right trapezoid, BA\perp AD , CD\perp AD , CD = 2AB , PA \perp base ABCD , E is the midpoint of PC , PA = AD .

Prove BE\perp plane PDC

Given pyramid P-ABCD , its base ABCD is a right trapezoid, BA\perp AD , CD\perp AD , CD = 2AB , PA \perp base ABCD , E is the midpoint of PC , PA = AD .

Prove BE\perp plane PDC