f.3 math question(percentage)
2012-11-06 4:59 am
if the base of a triangle is increased by60%,find the percentage in the height of the triangle so that its area remain unchanged
回答 (2)
2012-11-06 5:41 am
參考: maeducation.edu.hk
2012-11-06 10:33 pm
let B, H be the original base and height of triangle
such that the area = BH/2
new base = 1.6B
new height = h
area: (1.6B)h/2 = BH/2 => h = H/1.6
% change = 100% x (new - original) / original
= 100% x (H/1.6 - H) / H
= -37.5%
(negative value means it decreases)
such that the area = BH/2
new base = 1.6B
new height = h
area: (1.6B)h/2 = BH/2 => h = H/1.6
% change = 100% x (new - original) / original
= 100% x (H/1.6 - H) / H
= -37.5%
(negative value means it decreases)
收錄日期: 2021-04-16 15:11:48
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20121105000051KK00503