求步驟
http://img833.imageshack.us/img833/4521/img746q.jpg
F5 數學一條問題2
2012-11-02 6:27 am
回答 (2)
2012-11-02 7:17 am
✔ 最佳答案
8.∠ACB = 90° (半圓內圓周角)
∠ACF = ∠ABD (對同弧圓周角)
所以，∠ACF = x°
∠ACB + ∠CAB + ∠ABC = 180° (Δ內角和)
90° + y° + (54 + x°) = 180°
x + y = 36 ...... [1]
ΔACF 中：
∠CAB = ∠ACF + ∠AFC (Δ外角)
y = x + 20 ...... [2]
把 [2] 代入 [1] 中 :
x + (x + 20) = 36
2x = 16
x = 8
把 x = 8 代入 [2] 中：
y = 8 + 20
y = 28
參考: fooks
2012-11-02 6:43 am
個圖出唔到,你再上載過啦.
收錄日期: 2021-04-13 19:05:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121101000051KK00610