∵AE⊥BC,AF⊥CD∴∠AEC=∠AEB=90°,∠AFD=∠AFC=90°在四边形AECF中∵∠EAF=45°∴∠ECF=135°∵AB∥CD∴∠B+∠ECF=180°∠B=180°-135°=45°在等腰直角三角形ABF中∵AE=BE∴AB=√2 AE∵∠B=∠D∴△AFD也为等腰直...