b) 計到係30度
c) 唔識!
列明步驟THX!
圖片參考：http://a.imageshack.us/img693/5561/0007gp.jpg
更新1:
http://a.imageshack.us/img693/5561/0007gp.jpg
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2010-07-14 9:18 pm
a) 證到係AAA
b) 計到係30度
c) 唔識!
列明步驟THX!
圖片參考：http://a.imageshack.us/img693/5561/0007gp.jpg
b) 計到係30度
c) 唔識!
列明步驟THX!
圖片參考：http://a.imageshack.us/img693/5561/0007gp.jpg
回答 (2)
2010-07-14 9:53 pm
✔ 最佳答案
∵ AD = DF∴ ∠ DAF = ∠ DFA (base Ðs, isos. D)
∠ EDF = 2x30° (ext. Ð of D)
= 60°
DF/DE = cos60° = 1/2
OD = DE/2 = DF = AD
OA = OD + AD = 2OD
Ratio of the radii = 1:2 (or 2:1)
2010-07-14 9:20 pm
個圖看不全.....
收錄日期: 2021-04-21 22:13:52
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100714000051KK00658