设顶角为A,两底角为B和C,D是两个底角的角平分线的交点
求∠BDC
∵∠A = 150°
∴∠B + ∠C = 30°
∵D是两个底角的角平分线的交点
∴∠DBC + ∠DCB = (∠ABC+∠ACB)/2 = 15°
∴∠BDC = 180°-(∠DBC + ∠DCB)=165°
设顶角为A,两底角为B和C,D是两个底角的角平分线的交点
求∠BDC
∵∠A = 150°
∴∠B + ∠C = 30°
∵D是两个底角的角平分线的交点
∴∠DBC + ∠DCB = (∠ABC+∠ACB)/2 = 15°
∴∠BDC = 180°-(∠DBC + ∠DCB)=165°