http://upload.lsforum.net/users/public/d322872014-07-%20017v147.jpg
我選B,不知對不對
http://upload.lsforum.net/users/public/c368902014-07-%20015u147.jpg
做法及答案對嗎?
謝謝!
F5 Maths
2014-08-01 2:53 pm
回答 (2)
2014-08-01 8:47 pm
✔ 最佳答案
11.
答案： B. 8 cm
連 OB。
OB = OB (公共邊)
OM = ON (已知)
∠OMB = ∠ONB = 90° (已知)
ΔOMB ≅ ΔONB (RHS)
BN = BM = 4 cm (全等Δ對應邊)
BC = 4 x 2 cm = 8 cm (經圓心對弦作垂直線平分該弦)
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10.
答案： (C) 22
∠A = 90° (半圓內圓周角)
∠B = 180° - (90° + 35°) = 55° (Δ內角和)
圓周角與所對弧長成正比：
弧AC / 弧AB= ∠B / ∠C
弧AC / 14 = 55 / 35
弧AC = 14 x (55 / 35) = 22
參考: 土扁
2014-08-01 3:08 pm
You are right on both questions.
收錄日期: 2021-04-15 16:03:42
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140801000051KK00026