题目如图,AC⊥BCAC\bot BCAC⊥BC,AD⊥BDAD\bot BDAD⊥BD,AD=BCAD=BCAD=BC,CE⊥ABCE\bot ABCE⊥AB,DF⊥ABDF\bot ABDF⊥AB,垂足分别是EEE,FFF,求证:①△ABC\triangle ABC△ABC≌△BAD\triangle BAD△BAD；②CE=DFCE=DFCE=DF.知识点：相似三角形的判定I章节：图形的变化 / 图形的相似
如图,,,,,,垂足分别是,,求证:如图,,,,,,垂足分别是,,求证:如图,,,,,,垂足分别是,,求证: