✔ 最佳答案
Link:
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2011-06-02 17:56:15 補充:
謝謝樓上001的意見
第一題若以根式表示,答案應該是:
(x/tan36°)(2x)/2=10
x^2=10tan36°
x=√(10tan36°)
Perimeter is 10√(10tan36°)
=10√10√tan36°
From Exact Trigo. Value: tan36°=√(5-2√5)
Perimeter is 10√10(5-2√5)^(1/4)