如图,在三角形ABC中,AB=AC,BD是角平分线,若角BDC=69,则A=_

问题描述:

如图,在三角形ABC中,AB=AC,BD是角平分线,若角BDC=69,则A=_

32确定吗? 怎么算的确定 你画个图看下就知道了∠BDA = 180 - 69 = 111∠ABC=∠C=2∠DBC∠BDA =∠DBC+∠C=3∠DBC = 111所以∠DBC = 37∠C = 2∠DBC = 74∠ABC = ∠C =74所以 ∠A = 32