AB=AC.
证明:AE=CE,则OE垂直AC;同理可证:OD垂直AB.
又OE=OD.故AB=AC.(在同圆或等圆中,弦心距相等,则对应的弦也相等)
(注:在证明OE垂直AC,OD垂直AB后,也可证明Rt⊿OAE≌Rt⊿OAD,则AE=AD,故AC=AB.)
AB=AC.
证明:AE=CE,则OE垂直AC;同理可证:OD垂直AB.
又OE=OD.故AB=AC.(在同圆或等圆中,弦心距相等,则对应的弦也相等)
(注:在证明OE垂直AC,OD垂直AB后,也可证明Rt⊿OAE≌Rt⊿OAD,则AE=AD,故AC=AB.)