D是否是在BC上?如果是,则
∵BD=AD
∴∠DBA=∠DAB,
∵DC=AC
∴∠CAD=∠CDA=∠DBA+∠DAB=2∠DBA
∵AB=AC
∴∠DBA=∠DCA
∴∠CDA=∠CAD=2∠DCA
∵△CDA中,内角和为180°
∴∠DCA=180°/(1+2+2)=36°
∴∠ABC=∠ACB=36°,∠BAC=108°
谢谢