题目如图,AC⊥BCAC\bot BCAC⊥BC,BD⊥ADBD\bot ADBD⊥AD,垂足分别为CCC、DDD,AC=BDAC=BDAC=BD.求证:∠CAB=∠DBA\angle CAB=\angle DBA∠CAB=∠DBA.知识点：平行线的性质章节：图形的性质 / 相交线与平行线
如图,,,垂足分别为、,.求证:.如图,,,垂足分别为、,.求证:.如图,,,垂足分别为、,.求证:.