题目如图,∠ACB=90∘\angle ACB=90^{\circ}∠ACB=90∘,AC=BC.AD⊥CEAC=BC.AD\bot CEAC=BC.AD⊥CE,BE⊥CEBE\bot CEBE⊥CE,垂足分别是点DDD、EEE,AD=3AD=3AD=3,BE=1BE=1BE=1,则DEDEDE的长是______.知识点：全等三角形的判定章节：未标注
如图,,,,垂足分别是点、,,,则的长是______.如图,,,,垂足分别是点、,,,则的长是______.如图,,,,垂足分别是点、,,,则的长是______.