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michelle_winner 发表于 2009-11-5 04:24

请教大侠们一道路几何题?谢谢

L1 and L2 are two parallel lines, B,E and A, D, C, G, F are dots on L1 and L2, respecitvely. If BE= ED, the area of triangle ABC and DEF are 12 and 16, separately, then, Col A: length of DC, Col: 4.4Y5Q#U2w/C,yo

)vj9b*X9YQ&XQ3^w 如题, 谢谢啦

wang86894864 发表于 2009-11-5 11:12

G点为什么没用上?题对吗?

michelle_winner 发表于 2009-11-5 14:35

[quote]原帖由 [i]wang86894864[/i] 于 2009-11-5 11:12 发表 [url=http://bbs.taisha.org/redirect.php?goto=findpost&pid=15900792&ptid=1378605][img]http://bbs.taisha.org/images/common/back.gif[/img][/url]
^i2^d~f G点为什么没用上?题对吗? [/quote]
d9}7c6VF sorry, not"G", should be "E"!
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sorry about that
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.IL*{_m:w:T1J lP thanks

Dincy 发表于 2009-11-5 16:19

回复 3# michelle_winner 的帖子

那DEF就是一条直线了啊

michelle_winner 发表于 2009-11-6 00:02

L1 and L2 are two parallel lines, B,E and A, D, C, F are dots on L1 and L2, respecitvely. If BE= ED, the area of triangle ABC and DEF are 12 and 16, separately, then, Col A: length of DC, Col: 4. Pa^@4u`)tD
再发一遍,多写了一个字母, 不好意思!
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a ob"v/GO Gs.d 呵呵

Sangelf 发表于 2009-11-8 17:20

10.29考试的时候见过这个,但不是楼主描述的这样...{U_ ~};}B
我记得当时题是B,E在L1上,ADCF在L2上,三角形ABC面积小于三角形DEF,问AD和CF哪个大...其实这样只不过是两个夹在平行线的三角形,因为等高,所以面积的大小差别在底长度上,很好判断的。O&\a_8G$iI$~M^

)jhrL2fL j 如果按照楼主描述的,给出BE=ED,和三角形面积,是无法判断DC长度的...DC长度和三角形面积无关

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