延长AD到F,使DF=AD
则三角形ABD相似FCD
∠ABC=∠BCF、CF=AB=CE
∠ACF=∠ACE( ∠ACE =∠BAC+∠B=∠ACB+∠FCB=∠ACF)
AC=AC
所以AFC全等AEC
所以角DAC=角CAE