希望大家能幫幫手解答一下以下的問題~
1.
ab is a buliding with height 100m . the angle of elevation of a fromｃis２０度 what is the distance between b and c?
2.given the volume of a hemisphere is 18批 cm3次方
find its radius.
3.the heights of two similar pyramids is 18 cm and 20cm respectively . find the ratio of their volume.
數學高手入~即日回答
2007-09-03 6:10 am
回答 (3)
2007-09-03 6:20 am
✔ 最佳答案
1,abc is a right angle triangle ... with bc as base
so you can use tangent to solve for bc
tan 20 = 100 / bc
bc = 274.75 (m)
2, 批 = Pi , r = radius
volume of sphere (球體) = 4批r3次方 / 3
volume of hemisphere (半球) = 2批r3次方 / 3
2批r3次方 / 3 = 18批
2批r3次方 = 54批
r3次方 = 27
r = 3 (cm)
3,
length ratio 3次方 = volume ratio
(18/20) 3次方 = volume ratio
(9/10)3次方 = volume ratio
volume ratio = 729 / 1000
volume ratio is 729 : 1000
2007-09-03 6:47 am
1,
tan 20 = 100 / bc
bc = 274.75 (m)
2,
2批r3次方 / 3 = 18批
2批r3次方 = 54批
r3次方 = 27
r = 3 (cm)
3,
length ratio 3次方 = volume ratio
(18/20) 3次方 = volume ratio
volume ratio is 729 : 1000
tan 20 = 100 / bc
bc = 274.75 (m)
2,
2批r3次方 / 3 = 18批
2批r3次方 = 54批
r3次方 = 27
r = 3 (cm)
3,
length ratio 3次方 = volume ratio
(18/20) 3次方 = volume ratio
volume ratio is 729 : 1000
2007-09-03 6:28 am
1)tan20=100/BC
BC=274.74
2)1/2(4/3批R^3)=18批 cm3次方
2/3批R^3=18批 cm3次方
R^3=27
R=3
3.(18/20)^3=the ratio of their volume.
1:1.37
BC=274.74
2)1/2(4/3批R^3)=18批 cm3次方
2/3批R^3=18批 cm3次方
R^3=27
R=3
3.(18/20)^3=the ratio of their volume.
1:1.37
收錄日期: 2021-04-23 20:16:09
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20070902000051KK05111