Re: [問題] 國中數學
※ 引述《w3179w (去冰無糖綠)》之銘言：
: A
: /|\
: D /_|_\E
: / | \
: B /___|___\C
: 已知DE//BE 若將DE把ABC的面積分成二等分
: 且A點到BC的距離為12 則A到DE的距離為?
: 剛剛我國二的弟弟問我問題
: 我算不出來= =
: 請數學達人跟我講解一下重點觀念 我在自己算吧
令BC=X
且A垂足於BC中點F
則,BC : AF= X : 12
令DE=Y
DE交AF於G點(.......我承認我想歪了)
AG=Z
=>2YZ=12X
且已知Y:Z=X:12
=>2x(Xk)x(12k) = 12X
=>24Xk^2 = 12X
=>k=根號1/2=(根號2)/2
=>(根號2)/2 x 12 = 6根號2
懶的用符號表= =不好意思...
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http://www.wretch.cc/blog/xx41102 (大家好糟糕.........)
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◆ From: 114.198.162.138
※ 編輯: xx41102 來自: 114.198.162.138 (10/12 19:39)
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