本區搜索:
Yahoo!字典
打印

[Core] Deductive Geometry Problem

[隱藏]

Deductive Geometry Problem



the c Part spend me 1 hr !


pls help
   

TOP

已知
1. 題目: BC = DE
2. 題目: <BCE = <CAD
3. (a)已證: <ADE = <ACB
4. (b)已證: 三角ABC跟三角AED同等
5. (c)提供: AD//BC

問題: AB x AE = BF x DE
其實貿貿然相乘我就真係唔識做
估計你資料(1)-(3)已用
而且問題涉及邊長考慮所以(1)-(3)未必太直接有用
(4)讓我聯想起比例
- AB = AE
- BC = ED
- CA = DA
問題: AB x AE = BF x DE
AB已有
AE已有
DE也有
未知數就係BF
而BF = BC-CF = ED-CF

未用資料: AD//BC
所以
- <AFB = <FAD = <BAC (因為同等三角)
- <DAC = <BCA
- <ADC+<ACF+<DCA = 180, 即2<ACF+<DCA = 180
- <ADC = <BCE

回到問題
仍有未知數CF
而要將邊長跟角度掛勾就只有相似三角
涉及CF既三角一係ACF一係就CEF
咁ACF應該冇邊個相似既
咁CFE呢? AFB幫唔幫到手?

試一試吧
<AFB = <CFE (vert. opp. <)
<ABF = <CEF (因為<ABC = <AED, 已證同等三角)
證據夠了嗎?
如是者CF邊長又可以同邊條邊長成比例呢?

TOP

已知
1. 題目: BC = DE
2. 題目: <BCE = <CAD
3. (a)已證: <ADE = <ACB
4. (b)已證: 三角ABC跟三角AED同等
5. (c)提供: AD//BC

問題: AB x AE = BF x DE
其實貿貿然相乘我就真係唔識做
估計你資料(1)-(3)已用
而且問題涉及邊長考慮所以(1)-(3)未必太直接有用
(4)讓我聯想起比例
- AB = AE
- BC = ED
- CA = DA
問題: AB x AE = BF x DE
AB已有
AE已有
DE也有
未知數就係BF
而BF = BC-CF = ED-CF

未用資料: AD//BC
所以
- <AFB = <FAD = <BAC (因為同等三角)
- <DAC = <BCA
- <ADC+<ACF+<DCA = 180, 即2<ACF+<DCA = 180
- <ADC = <BCE

回到問題
仍有未知數CF
而要將邊長跟角度掛勾就只有相似三角
涉及CF既三角一係ACF一係就CEF
咁ACF應該冇邊個相似既
咁CFE呢? AFB幫唔幫到手?

試一試吧
<AFB = <CFE (vert. opp. <)
<ABF = <CEF (因為<ABC = <AED, 已證同等三角)
證據夠了嗎?
如是者CF邊長又可以同邊條邊長成比例呢?

TOP

Thank you thank to thank him and for him to get the stuff done for him I don't think you ever get it to go get your hair cut off your car thank goodness you got a job I would be a little more excited about your new car if I don't know you know how I got you know you love him I will talk about you and you bye thank him bye thank everyone bye love him and then you will see it again I don't think he will get any money or he wants him back in a while I will get them back and let them get them bye love bye see what they have for me I love him thank him bye thank him love bye thank goodness

TOP

jyahayahagah

TOP

重要聲明:小卒資訊論壇 是一個公開的學術交流及分享平台。 論壇內所有檔案及內容 都只可作學術交流之用,絕不能用商業用途。 所有會員均須對自己所發表的言論而引起的法律責任負責(包括上傳檔案或連結), 本壇並不擔保該等資料之準確性及可靠性,且概不會就因有關資料之任何不確或遺漏而引致之任何損失或 損害承擔任何責任(不論是否與侵權行為、訂立契約或其他方面有關 ) 。