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更新1:
要步驟.......
maths~~~~~~~~!
2010-01-20 6:56 am
回答 (1)
2010-01-20 7:03 am
✔ 最佳答案
AB = 2EF ......AB : EF = 2 : 1BC = 2DF.......BC : DF = 2 : 1
AC = 2DE.......AC : DE = 2 : 1
所以△ABC ~ △EFD(對應邊成比例)
△ABC : △DEF = (AB : EF)^2 = (2 : 1)^2
△ABC : 18 = 2^2
△ABC = 18 x 2^2 =72cm^2
收錄日期: 2021-04-21 22:14:30
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100119000051KK01727