※ 引述《zx153w (oWWWWWWWWWWWo)》之銘言：
: http://i.imgur.com/6MEHc3d.jpg
: 想很久…但沒什麼想法
: 想不到要怎麼起手破解
DE = a
AE = b
△AEF = △FBC = △EDC = A
△FBE = [(b)/(a + b)] △FBC = [b/(a + b)]A
[△AEF + △FBE] : △EDC = b :ａ
=> [1 + b/(a + b)] : 1 = b : a
令x = b/a
=> [1 + 2x]/[1 + x] = x
=> x^2 - x - 1 =
=> b/a = (1/2)[1 + √5]
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