If each side of anequilateral triangle is decreasd by 2 cm, the perimeter of the new triangle is 4/5 that of the origianl one.
Find the length of a side of the origianal triangle.
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中一 [Maths]
2007-12-19 5:21 am
回答 (2)
2007-12-19 5:34 am
✔ 最佳答案
一個等邊三角形的每條邊都減少2厘米，新三角形的周界是原本三角形的４／５，求原本三角形的邊長。首先，我們假設每條邊長Ｘ厘米
Let y be the length of a side of the original triangle.
(新三角形的周界) 3(y-2)=3y x 4/5 (原本三角形的周界的4/5)
3y-3x2=2.4y
3y-6=2.4y
3y-2.4y=6
0.6y=6
y=6/0.6
y=10
∴the length of a side of the original triangle is 10cm.
2007-12-19 5:30 am
如果個３角形ｇｅ每１條邊長２ｃｍ，個新周界係本來ｇｅ４／５
佢問ｅ＋你個邊長係幾
ｙ係之前ｇｅ邊長
（ｙ＋２）ｘ３＝（４／５）３ｙ
（ｙ＋２）ｘ４／５＝ｙ
佢問ｅ＋你個邊長係幾
ｙ係之前ｇｅ邊長
（ｙ＋２）ｘ３＝（４／５）３ｙ
（ｙ＋２）ｘ４／５＝ｙ
參考: 我
收錄日期: 2021-04-13 22:04:22
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071218000051KK03594