Re: [中學] 一題國中圓冪
: 請各位先進幫忙，謝謝
△DBC為等腰三角形
△BDE ~ △ADB
=> AD : DB = BD : DE
=> BD^2 = AD * DE = 8 * 2 = 16
=> BD = 4
=> CD = 4
BE : DE = AB : BD
=> BE = AB * 2/4
△ADC ~ △CDE
=> CE : CD = AC : AD
=> CE = AC * 4/8
又BE * EC = AE * ED = 6 * 2 = 12
=> AB * AC * 1/4 = 12
=> AB * AC = 48
=> △ABC = (1/2) * AB * AC * 1/√2
= 12√2
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