http://img217.imageshack.us/img217/9707/0005h.jpg
上面果邊想不到如何證相似3角形thx`
最好有圖解釋thx`
下面果題，我咁寫得唔得?
as <CPA = <DPB (rept. opp. <s)
so CA=PB (equal angles, equal chords)
<CAD=<DPB (<s in the same segment)
so CAP=BDP (AAS)
as CP+PD = AP=PB
so AB=CD
(雖然我知有更簡單的方法-3-)
Circles
2010-04-27 5:54 am
回答 (1)
2010-04-27 6:22 am
✔ 最佳答案
3(a) The trick is that triangle ABC is similar to triangle PBA and PAC (AAA)So triangle APB ~ triangle CPA
(b)
PB/PA=PA/PC
PB/4=4/2
PB=8 cm
(c) radius=(8+2)/2=5 cm
3 Your method is wrong. CA=DB (equal angles, equal chords) ????
First triangle OPQ ~= triangle OPR (AAS)
Second triangle OQC ~= triangle ORB (RHS)
So BP=PC
Now angle CPA = angle BPD
angle ACP = angle DBP
So triangle ACP ~= triangle DBP
AP=DP
Just AP+PB=DP+PC
AB=CD
收錄日期: 2021-04-26 14:55:08
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100426000051KK01616