Isosceles triangle have equal angles

Consider isosceles triangle ABC with AB=AC  

Draw AD such that it bisects ^BAC

Consider triangles ABD and ACD

     AB=AC                 (Given)

     AD=AD                 (Common)

   ^BAD=^CAD               (Construct)

So

tri.ADB=tri.ACD                     (2 sides & inc ang equal)

So

   ^ABC=^CBA