满分5 >
初中数学试题 >
一架5米长的梯子斜靠在墙上,测得它与地面的夹角为40°,则梯子底端到墙角的距离为...
一架5米长的梯子斜靠在墙上,测得它与地面的夹角为40°,则梯子底端到墙角的距离为( )
A.5sin40°
B.5cos40°
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107012_ST/0.png)
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107012_ST/1.png)
考点分析:
相关试题推荐
如图,在△ABC中,∠A=30°,tanB=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107011_ST/0.png)
,AC=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107011_ST/1.png)
,则AB=( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107011_ST/images2.png)
A.4
B.5
C.6
D.7
查看答案
在直角三角形ABC中,斜边AB=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107010_ST/0.png)
,且tanA+cotA=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107010_ST/1.png)
,则△ABC的面积等于( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107010_ST/2.png)
B.6
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107010_ST/3.png)
D.2
查看答案
某装饰公司要在如图所示的五角星形中,沿边每隔20厘米装一盏闪光灯.若BC=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107009_ST/0.png)
-1米,则需安装闪光灯( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107009_ST/images1.png)
A.100盏
B.101盏
C.102盏
D.103盏
查看答案
在△ABC中,已知∠C=90°,BC=4,sinA=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107008_ST/0.png)
,那么AC边的长是( )
A.6
B.2
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107008_ST/1.png)
C.3
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107008_ST/2.png)
D.2
查看答案
如图,△ABC中,∠ACB=90°,∠B=30°,AC=1,过点C作CD
1⊥AB于D
1,过点D
1作D
1D
2⊥BC于D
2,过点D
2作D
2D
3⊥AB于D
3,这样继续作下去,线段D
nD
n+1(n为正整数)等于( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107007_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107007_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107007_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101408135710790/SYS201311031014081357107007_ST/2.png)
D.
查看答案