摘要：18．····························································································································································· 等腰三角形ABC底边上的高AD＝BC.AB＝.则△ABC面积为··················································································· ( )． (A) 2 (D)4
网址：http://m.1010jiajiao.com/timu3_id_767938[举报]
做如下操作：在等腰三角形ABC中，AB＝AC，AD平分∠BAC交BC于点D，将△ABD作关于直线AD的轴对称变换，所得的像与△ACD重合，对于下列结论：
①在同一个三角形中，等角对等边；
②在同一个三角形中，等边对等角；
③等腰三角形的顶角平分线、底边上的中线和高互相重合；
由上述操作可得出的是
[ ]
A．①②③
B．①②
C．①③
D．②③
