满分5 >
初中数学试题 >
全市人民总动员,修建海堤抗台风,某海堤的横断面为梯形,如图所示.迎水坡坡角为30...
全市人民总动员,修建海堤抗台风,某海堤的横断面为梯形,如图所示.迎水坡坡角为30°,背水坡AD的坡比为1:1.2,堤顶宽DC为3m,堤高CF为10m,则堤坝底宽AB约为( )(精确到0.1m,
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467014_ST/0.png)
≈1.732)
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467014_ST/images1.png)
A.32.3m
B.29.3m
C.28.6m
D.21m
考点分析:
相关试题推荐
已知:一个等腰直角三角形腰长为a,三边上的高之积为P,一个等边三角形边长为a,三边上的高之积为Q,则P和Q的大小关系是( )
A.P>Q
B.P<Q
C.P=Q
D.无法确定
查看答案
若等腰三角形的顶角是120°,底边长为2cm,则它的腰长为( )
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467012_ST/0.png)
cm
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467012_ST/1.png)
cm
C.2cm
D.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467012_ST/2.png)
cm
查看答案
已知:如图,在Rt△ABC中,∠C=90°,AB=10,sinB=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467011_ST/0.png)
,BC的长是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467011_ST/images1.png)
A.2
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467011_ST/1.png)
B.4
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467011_ST/2.png)
D.
查看答案
如图,在△ABC中,∠A=30°,E为AC上一点,且AE:EC=3:1,EF⊥AB于F,连接FC,则tan∠CFB等于( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467010_ST/images0.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467010_ST/0.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467010_ST/1.png)
C.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467010_ST/2.png)
D.
查看答案
如图,Rt△ABC中,∠C=90°,D为BC上一点,∠DAC=30°,BD=2,AB=
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467009_ST/0.png)
,则AC的长是( )
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467009_ST/images1.png)
A.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467009_ST/1.png)
B.
![manfen5.com 满分网](http://img.manfen5.com/res/CZSX/web/STSource/20131103101458204046704/SYS201311031014582040467009_ST/2.png)
C.3
D.
查看答案