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 $$ PDC $$

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 $$ PDC $$

Question