[10pt]geometry
2008-08-28 8:25 am
圖片參考：http://i271.photobucket.com/albums/jj157/kimkim0513/MathQs.jpg
prove that
AB+AC>DB+DC
use knowledge at f2 level
回答 (1)
2008-08-28 6:30 pm
✔ 最佳答案
In a triangle, the sum of the lengths of any two sides must be greater than the length of the third side.
Consider ∆ADC:
AD + AC > DC
Add DB to both sides of the inequality:
DB + AD + AC > DB + DC
(DB + AD) + AC > DB + DC
But DB + AD = AB
Hence, AB + AC > DB + DC
=
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原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20080828000051KK00093