题目已知:EF⊥ABEF\bot ABEF⊥AB,CD⊥ABCD\bot ABCD⊥AB,∠EFB=∠GDC\angle EFB=\angle GDC∠EFB=∠GDC,求证:∠AGD=∠ACB\angle AGD=\angle ACB∠AGD=∠ACB.知识点：垂线章节：图形的性质 / 相交线与平行线
已知:,,,求证:.已知:,,,求证:.已知:,,,求证:.