F1 數學難題,幫幫手吧!
2010-07-14 6:03 am
1.In the figure,an equilateral triangle is vut into 9 equal equilateral triangle triangles.If the total perimeter of the 9 small triangle is 54cm more than the perimeter of the original triangle, find the length of a side of the original triangle
回答 (3)
2010-07-14 6:17 am
✔ 最佳答案
Let x cm be the length of a side of the smaller triangleFigure:
圖片參考：http://img704.imageshack.us/img704/9599/mathj.png
From the figure, there are 18 sides of smaller triangle(with equal length of x)
and 3 sides of the bigger triangle(with equal length of 3x)
So, the equation should be set like below:
18x - 3(3x) = 54
18x - 9x = 54
9x = 54
x = 6
The length of a side of the original triangle = 3(6) = 18 cm
2010-07-13 22:19:15 補充：
Amendment:
with equal length of x cm
with equal length of 3x cm
參考: Knowledge is power.
2010-07-19 8:53 pm
If length of side of the small triangles is x cm,
then length of side of the original triangle is 3x cm.
Total perimeter of the 9 small triangles is 54cm more than the perimeter of the original triangle:
9*3x-3*3x=54
(9-3)3x=54
3x=54/6=9(cm)
then length of side of the original triangle is 3x cm.
Total perimeter of the 9 small triangles is 54cm more than the perimeter of the original triangle:
9*3x-3*3x=54
(9-3)3x=54
3x=54/6=9(cm)
2010-07-14 6:26 am
From the figure, there are 18 sides of smaller triangle(with equal length of x)
and 3 sides of the bigger triangle(with equal length of 3x)
So, the equation should be set like below:
18x - 3(3x) = 54
18x - 9x = 54
9x = 54
x = 6
The length of a side of the original triangle = 3(6) = 18 cm
and 3 sides of the bigger triangle(with equal length of 3x)
So, the equation should be set like below:
18x - 3(3x) = 54
18x - 9x = 54
9x = 54
x = 6
The length of a side of the original triangle = 3(6) = 18 cm
收錄日期: 2021-04-25 17:01:55
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100713000051KK01810