
Re: [中學] 幾何一題

: 為什麼超難 QQ
: 謝謝
∠D = 40
∠ACD = 40 + 30 = 70
∠CAD = 180 - 40 - 70 = 70
(C)
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答案還是剛好70
在CD下找一點E使得△DCE = △ABC
∠DEC = 110 = ∠ACE
又因為CA = ED
所以ACED為等腰梯形
=> ∠CAD = 70
(C)
※ 編輯: Honor1984 (114.44.195.190), 11/02/2014 01:38:53
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