http://i1262.photobucket.com/albums/ii606/lemonyeung/circle.jpg 唔明點解點出呢條式 (72+2*72)/2=108 (螞蟻雄兵答案)?
回答 (1)
2015-10-11 11:59 am
✔ 最佳答案
Let arc(AD) = arc(AB) = arc(BC) = y=> arc(CD) = 2y
arc(AD + AB + BC + CD)
= 3y + 2y
= 5y = 180°
=> y = 36°
Link AD, X = AC ∩ BD, ΔXAD:
x = ∠XAD + ∠ADX
= arc(CD) + arc(AB)
= 2y + y
= 3y
= 3*36°
= 108°
= (A)
收錄日期: 2021-04-24 09:57:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20151011023843AAEaV30