满分5 >
高中数学试题 >
已知三棱锥的三个侧面两两垂直,三条侧棱长分别为4,4,7,若此三棱锥的各个顶点都...
已知三棱锥的三个侧面两两垂直,三条侧棱长分别为4,4,7,若此三棱锥的各个顶点都在同一球面上,则此球的表面积是( )
A.81π
B.36π
C.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846006_ST/0.png)
π
D.144π
考点分析:
相关试题推荐
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846005_ST/images0.png)
如图,在四面体ABCD中,截面PQMN是正方形,则在下列命题中,错误的为( )
A.AC⊥BD
B.AC∥截面PQMN
C.AC=BD
D.异面直线PM与BD所成的角为45°
查看答案
设m,n是两条不同的直线,α,β是两个不同的平面,下列命题正确的是( )
A.若m⊥n,m⊥α,n∥β,则α∥β
B.若m∥α,n∥β,α∥β,则m∥n
C.若m⊥α,n∥β,α∥β,则m⊥n
D.若m∥n,m∥α,n∥β,则α∥β
查看答案
若a,b是异面直线,直线c∥a,则c与b的位置关系是( )
A.相交
B.异面
C.平行
D.异面或相交
查看答案
已知向量
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846002_ST/0.png)
=(2,3,1),
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846002_ST/1.png)
=(1,2,0),则|
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846002_ST/2.png)
-
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846002_ST/3.png)
|等于( )
A.1
B.
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846002_ST/4.png)
C.3
D.9
查看答案
如图,在正方体ABCD-A
1B
1C
1D
1中,异面直线A
1B与D
1A所成的角等于( )
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131103100606571884694/SYS201311031006065718846001_ST/images0.png)
A.45°
B.60°
C.90°
D.120°
查看答案