∵AD平分∠CAB交BC于点D∴∠CAD=∠EAD ∵DE⊥AB∴∠AED=∠C=90∵AD=AD∴△ACD≌△AED.(AAS)∴AC=AE,CD=DE∵∠C=90°,AC=BC∴∠B=45°∴DE=BE∵AC=BC,AB=6cm,∴2BC 2 =AB 2 ,即BC= AB 2 2 = 6 2 2 =3 2 ,∴BE=AB-AE=AB-AC=6-3
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