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[几何] 锐角三角形四心共线

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guanmo1 Posted 2018-4-29 21:58 |Read mode
Last edited by hbghlyj 2025-5-4 07:35在锐角△ABC中,边BC为最小边,点O、G、I、H分别是它的外心、重心、内心、垂心当OG = GI = IH时,则AB: AC: BC =

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isee Posted 2018-4-30 06:51
回复 1# guanmo1

先研究欧拉线,绝对和这个脱不了关系

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 Author| guanmo1 Posted 2018-4-30 07:02
回复 2# isee


    欧拉线知道,说明现在四心依次等距离排列,然后咋办呢?

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isee Posted 2018-4-30 11:29
回复 3# guanmo1

仅提供个方向,未深入思考。。。。个人感觉上,向量可行。

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abababa Posted 2018-4-30 19:00
回复 1# guanmo1

这个是在标题里说的四心共线,我发给网友,网友问在题目里有没有四心共线,如果共线,这一定是等腰三角形,满足条件的锐角三角形三边比是$2:2:1$,钝角三角形三边比是$2:2:3$

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 Author| guanmo1 Posted 2018-5-2 23:35
由已知条件,结合欧拉线,就是四心共线啊。确实是等腰三角形,边长比为2:2:1,已解决,谢谢啦!

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abababa Posted 2018-5-3 17:41
回复 6# guanmo1
请教怎么证明这四心共线?欧拉线我是知道的,但是怎么证明内心也一定在欧拉线上?

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kuing Posted 2018-5-3 18:11
回复 7# abababa

两边之和等于第三边啊

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abababa Posted 2018-5-3 20:32
回复 8# kuing

原来如此,忽略了基本的知识点。

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