题目如图,ABABAB是⊙O\odot O⊙O的直径,弦CD⊥ABCD \perp ABCD⊥AB,垂足为HHH.EEE为◯∼\bigcirc\sim◯∼上一点,连结AEAEAE交CDCDCD于点FFF,EFEFEF的垂直平分线交CDCDCD的延长线于点GGG,连结GEGEGE.(1)若 ⊙O\odot O⊙O的半径为3, AH=2AH=2AH=2,求CD的长;(2)求证:EG是 ⊙O\odot O⊙O的切线.知识点:线段垂直平分线的性质、勾股定理、垂径定理、切线的判定章节:未标注