(1)证明:∵AB=DC,AC=DB,∴四边形ABDC是平行四边形;(2)解:连接AE,∵A( 3 ,0)为圆心作⊙A,⊙A与x轴相交于点B,C,与y轴相交于点D,E,且C点坐标为(3 3 ,0).∴OA= 3 ,OC=3 3 ,∴圆的半径长是:3 3 - 3 =2 3 ,在直角△OAE中,OE= AE2?OA2 =