An artist is working on a stained glass design made from a square ABCD and 4 identical triangles. He wants to decorate the square ABCD using a gold edge but he only has enough gold to plate an edge of length 60 cm.
Find the values of x and y if the artist uses up all the gold..
Figure: http://www.flickr.com/photos/51470019@N07/4853056268/
PLS help.. THX..
maths
2010-08-03 3:03 am
回答 (1)
2010-08-03 3:21 am
✔ 最佳答案
圖片參考：http://farm5.static.flickr.com/4080/4853056268_379f79c0c5.jpg
AB+BC+CD+DA = 60
4√(x^2 + y^2) = 60
x^2 + y^2 = 225 .....(1)
x + y = 21 .....(2)
By (2) , y = 21 - x , sub it to (1) ,
x^2 + (21 - x)^2 = 225
x^2 + 21^2 - 42x + x^2 = 225
2x^2 - 42x + 216 = 0
x^2 - 21x + 108 = 0
(x - 9)(x - 12) = 0
x = 9 or x = 12
so y = 12 or y = 9
By the graph x > y ,
x = 12 , y = 9
收錄日期: 2021-04-21 22:15:39
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100802000051KK01481