作者Honor1984 (奈何上天造化弄人？)
看板Math
标题Re: [中学] 几何一题
时间Sun Sep 24 00:07:48 2023
※ 引述《tuhunger (照片比本人帅)》之铭言：
: 题目如图，感谢各位提点
: https://i.imgur.com/AaKqq7O.jpg
设FD交GE於H
CG : GA = CE : EB
=> GE // AB 且 GE = (4/5)AB
=> FD垂直AB
设AD = 2x => DB = 3x，GE = 4x，HD = 2x = GH
GH = AD且HD垂直GH、AD
=> GHDA为正方形
=> GA = HD = 2x，GC = 8x
(10x)^2 + (5x)^2 = 15^2
正方形面积 = (2x√2)^2 = 8x^2 = 72/5
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1F：→ Honor1984 : GH = HD = AD且HD垂直GH、AD 09/24 00:16
2F：推 tuhunger : 漂亮唷 09/24 00:18
3F：推 reye : 好解法 09/25 18:51