分类：教育/科学-学习帮助
问题：解答题1.在三角形ABC中,角A=96度,延长BC到D,角ABC 
1.在三角形AB中,角A=96度,延长BC到D,角ABC与角ACD平分线交于A,角A1`BC与角A1`CD的平分线交于A2,依次类推,角A4`CD的平分线交于A5.求:角A5的大小.拜托大家能详细解题.
回答：∠A1=180-(∠A1BC+∠A1CA+∠BCA)
    =180-(1/2∠ABC+1/2∠ACD+∠BCA)
    =180-[1/2∠ABC+1/2(∠ABC+∠CAB)+∠BCA]
    =180-( ∠ABC+∠BCA+1/2∠CAB)
    =180-∠ABC-∠BCA-1/2∠CAB
    = ∠BAC-1/2∠BAC
    =1/2 ∠BAC
由此推论出∠A5=1/32∠BAC=1/32*96=3度