已知:△ABC中,AB=AC,BF,CE分别∠ABC,∠ACB的角平分线.求证:BF=CE,即等腰三角形的两底角的平分线相等证明:∵AB=AC,∴∠ABC=∠ACB,∵BF,CE分别∠ABC,∠ACB的角平分线,∴∠BCE=∠CBF,∵∠ABC=∠ACB,BC=BC,∴△BCE≌△CBF,∴BF=CE,即等腰三角形两底角的平分线相等.