Re: [中學] 國中數學問題請益

[Honor1984 (喬祺對我如此狠)]

※ 引述《yizihappyQ (Ms.Q)》之銘言：
: http://i.imgur.com/TnUYBW0.jpg
: 請問左上第8題怎麼解？
: 謝謝！

過D做AE平行線交BC於J

=> BJ = JE

DFEJ = 5 * 4 - 5 = 15

△DFE = △CFE = 5

=> △DJE = 15 - 5 = 10

=> △DJE = △BJD = 10

=> BEFD = 10 + 15 = 25

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→ Honor1984   : EF = 3 => DJ = 6 => AE = 12 => AF = 9