∵∠ABC的平分线交AC于点D,∴∠ABD = ∠DBC;∵圆O过B,D两点,∴OB,OD 为半径,设OB = OD = x∵OB = OD,∠ODB = ∠OBD = ∠ABD = ∠DBC∴OD // BC,三角形ACB 相似于三角形ADO∴OD/BC = AO/AB,OD = x,BC = 3,AB = 5,AO =...