求列式
No.1
Improve each of the following estimation:
(a)
40972/6～36000/6=6000
(b)
624x4~600x4=2400
No.2
(a)
Construct ����ABC such that AB=5cm, BC=6cm, AC=5cm.
(b)
Construct the perpendicular bisector of BC such that it meets BC at D.
(c)
Does the perpendicular bisector constructed in (b) pass through A?
No.3
Leo uses a ruler on which the distane between 2 successive markings is 5mm to measure the sides of a rectangle and here are the results:
Length=4.5 cm, Width =6.5cm
If he uses the measured lengths to calculate the are of the rectangle, find the
accumulated error in the result obtained.
F.1升F.2數學暑期作業 急!!!!!😌😓
2014-08-17 1:30 am
回答 (2)
2014-08-19 1:07 am
✔ 最佳答案
1a) 唔明(～) 補充b) 唔明(～) 補充
2a) 畫條bc先 再用圓規係2點畫5cm既圓 再將果點拉去b同c
b)畫條線同bc成90度 bd=cd
c)yes (ad=4cm)
3) upper length=4.5+0.25=4.75cm
lower length=4.5-0.25=4.25cm
upper width=6.5+0.25=6.75cm
lower width=6.5-0.25=6.25cm
Therefore, the area range is 4.25 X 6.25 (CM^2) <actual area < 4.75 X 6.75 (CM^2)
= 26.5625 cm^2 < actual area < 32.0625 cm^2
2014-08-18 17:11:35 補充：
1a) 40972/6～36000/6=6000 --> 40972/6～40800/6=6800
b) 624x4~600x4=2400 --> 624x4~620x4=2480
參考: , mememe
2014-08-17 7:06 am
第一條,
(a) 40972/6～36000/6=6000
用 36000 近似 40972 不太恰當,
因為 42000 比 36000 更加接近 40972,
40972 - 36000 = 4972
42000 - 40972 = 1028
2014-08-16 23:07:54 補充：
(b) 624x4~600x4=2400
620 比較恰當
2014-08-16 23:09:27 補充：
考慮 三角形ABC 是等腰三角形,
AB 和 AC 是等腰
2014-08-16 23:10:38 補充：
第3條
qid=7007081506830
不要只抄襲別人答案, 也要認真學習當中知識!
2014-08-16 23:12:29 補充：
希望不要刪本知識, 等後人可以參考!
(a) 40972/6～36000/6=6000
用 36000 近似 40972 不太恰當,
因為 42000 比 36000 更加接近 40972,
40972 - 36000 = 4972
42000 - 40972 = 1028
2014-08-16 23:07:54 補充：
(b) 624x4~600x4=2400
620 比較恰當
2014-08-16 23:09:27 補充：
考慮 三角形ABC 是等腰三角形,
AB 和 AC 是等腰
2014-08-16 23:10:38 補充：
第3條
qid=7007081506830
不要只抄襲別人答案, 也要認真學習當中知識!
2014-08-16 23:12:29 補充：
希望不要刪本知識, 等後人可以參考!
收錄日期: 2021-05-01 15:03:26
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20140816000051KK00102