题目如图,ABABAB、CDCDCD是⊙O\odot O⊙O的两条弦,AB^=CD^\widehat {AB}=\widehat {CD}AB=CD,OE⊥ABOE\bot ABOE⊥AB,OF⊥CDOF\bot CDOF⊥CD,垂足分别为EEE、FFF.求证OE=OFOE=OFOE=OF.知识点:垂径定理章节:图形的性质 / 圆