问题
填空题
如图,在△ABC中,∠C=90°,AC=BC,AD平分∠CAB交于BC于点D,DE⊥AB于点.若△DBE的周长是16cm,则边AB的长是______cm.

答案
∵AD是∠BAC的平分线,DE⊥AB,∠C=90°,
∴△ACD≌△AED,
∴CD=DE,AE=AC,
∴△DBE的周长
=DE+EB+DE
=CD+DB+EB
=BC+EB
=AC+EB
=AE+EB
=AB
=16cm.
如图,在△ABC中,∠C=90°,AC=BC,AD平分∠CAB交于BC于点D,DE⊥AB于点.若△DBE的周长是16cm,则边AB的长是______cm.
∵AD是∠BAC的平分线,DE⊥AB,∠C=90°,
∴△ACD≌△AED,
∴CD=DE,AE=AC,
∴△DBE的周长
=DE+EB+DE
=CD+DB+EB
=BC+EB
=AC+EB
=AE+EB
=AB
=16cm.