题目如图,四边形ABCDABCDABCD内接于⊙O\odot O⊙O,∠BAD=90∘\angle BAD=90^{\circ}∠BAD=90∘,BC^=CD^\widehat {BC}=\widehat {CD}BC=CD,过点CCC作CECECE,使得CE=CDCE=CDCE=CD,交ADADAD的延长线于点EEE.(1)(1)(1)求证:AB=AEAB=AEAB=AE；(2)(2)(2)若AD=DE=2AD=DE=2AD=DE=2,求⊙O\odot O⊙O的直径.知识点：切线的判定章节：图形的性质 / 圆
如图,四边形内接于,,,过点作,使得,交的延长线于点.如图,四边形内接于,,,过点作,使得,交的延长线于点.如图,四边形内接于,,,过点作,使得,交的延长线于点.