题目内容
.如图,在底面是直角梯形的四棱锥S-ABCD中,∠ABC=90°,SA⊥面ABCD,SA=AB=BC=1,AD=
.

(1)求四棱锥S-ABCD的体积;
(2)求证:面SAB⊥面SBC;
(3)求二面角
的正切值.


(1)求四棱锥S-ABCD的体积;
(2)求证:面SAB⊥面SBC;
(3)求二面角

(1)
;
(2)证明:见解析;(3)
。

(2)证明:见解析;(3)

(1)根据棱锥的体积公式
直接求解即可.
(2)根据面面垂直的判定定理,只需证明
平面
.
(3)解决本小题的关键是做(找)出二面角的平面角.过点
作
于
(
在
的延长线上,连接
,则
,所以
为二面角
的平面角.
(1)由棱锥体积公式:
----------4分
(2)证明:
,
,
,
平面
平面
,
面SAB⊥面SBC -----------8分
(3)过点
作
于
(
在
的延长线上,连接
,则
,所以
为二面角
的平面角.-------------------10分
在
中,
,所以
------------12分

(2)根据面面垂直的判定定理,只需证明


(3)解决本小题的关键是做(找)出二面角的平面角.过点









(1)由棱锥体积公式:

(2)证明:








(3)过点









在




练习册系列答案
相关题目