http://upload.ysk.hk/index-download-77522.html 問題+圖
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計角度啊...點樣計??
2008-01-25 4:36 am
回答 (2)
2008-01-25 4:47 am
✔ 最佳答案
a)∵BA//CO (已知)∴∠AOC + 32°= 180°(同側內角)
∠AOC = 148°
∴優角AOC = 360°﹣148°(同頂角)
= 212°
b)優角AOC = 2∠ABc (圓心角兩倍於圓周角)
212°= 2∠ABc
∠ABc = 212°/2
∠ABc = 106°
2008-01-24 20:48:40 補充：
∠ABC的C是大楷
2008-01-25 5:00 am
a. ∵BA//CO
∴∠ABC+∠BCO=180° (同側內角和)
∴優角AOC=360°-180°-32°=148°
b. 連接AC
可得優角AOC=2 x ∠ABC (圓周角2倍於圓心角)
∴∠ABC=148°÷2=74°
∴∠ABC+∠BCO=180° (同側內角和)
∴優角AOC=360°-180°-32°=148°
b. 連接AC
可得優角AOC=2 x ∠ABC (圓周角2倍於圓心角)
∴∠ABC=148°÷2=74°
參考: me
收錄日期: 2021-04-11 00:29:58
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080124000051KK03120