In the figure, OABCD is a sector of a circle. If arc AB = arc BC = arc CD,
then x = ?
圖片參考：http://imgcld.yimg.com/8/n/HA00149615/o/701112220071013873414250.jpg
F6 Maths 272
2011-12-23 2:39 am
回答 (1)
2011-12-23 3:47 am
✔ 最佳答案
ㄥCOD = 90/3 = 30°ㄥCAD
= (1/2)ㄥCOD (∠at centre twice ∠ at ☉ce)
= 15°
Similarly ,
ㄥBDA = 15°
x + ㄥCAD + ㄥBDA = 180° (ㄥ sum of △)
x + 15° + 15° = 180°
x = 150°
收錄日期: 2021-04-21 22:26:29
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20111222000051KK00710