The figure shows a square with side 12 cm. A corner is cut off along PQ with PB= QC If the area of the remaining part is 128cm^2, find the possible values of t.
要式.唔該
12cm
a |-------------------------| d
| |
| |
| | <--------正方形黎-_-
p| |
| |
b|_______________|
Q c
F.4 maths題目
2010-01-08 3:53 am
回答 (1)
2010-01-08 4:17 am
✔ 最佳答案
Let PB = t cmThen QB = (12 - t) cm
Area of triangle PBQ = (1/2)(t)(12 - t) = 6t - t^2 / 2
Area of remaining part = 12^2 - (6t - t^2 / 2)
= 144 - 6t + t^2 / 2
= 128
Therefore t^2 / 2 - 6t + 16 = 0
t^2 - 12t + 32 = 0
(t - 4)(t - 8) = 0
t = 4 or t = 8
收錄日期: 2021-04-23 23:21:34
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20100107000051KK01279