名校
解题方法
1 . 已知四棱锥
中,底面
为正方形,O为其中心,点E为侧棱
的中点.
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937213962313728/2938940206055424/STEM/0d4305f72296407892f1aa3ea1be8bf9.png?resizew=228)
(1)作出过O、P两点且与
平行的四棱锥截面(在答题卡上作出该截面与四棱锥表面的交线,并写出简要作图过程);记该截面与棱
的交点为M,求出比值
(直接写出答案);
(2)若四棱锥的侧棱与底面边长均相等,求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://img.xkw.com/dksih/QBM/2022/3/16/2937213962313728/2938940206055424/STEM/0d4305f72296407892f1aa3ea1be8bf9.png?resizew=228)
(1)作出过O、P两点且与
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7c21e3e66b01ebf71bb68cf88f6c1155.png)
(2)若四棱锥的侧棱与底面边长均相等,求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/68a83fdd2ba72a2dba0b6b10bb3e06b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
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名校
解题方法
2 . 如图的虚线网格纸上小正方形的边长为1,粗实线画出的是某几何体的三视图.在该几何体的直观图中,直线
与
所成角的余弦值为( )
![](https://img.xkw.com/dksih/QBM/2020/2/12/2397569787617280/2398867649388544/STEM/44e3a3fb-c39d-4a59-8295-49617b96307e.png?resizew=260)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://img.xkw.com/dksih/QBM/2020/2/12/2397569787617280/2398867649388544/STEM/44e3a3fb-c39d-4a59-8295-49617b96307e.png?resizew=260)
A.![]() | B.![]() | C.![]() | D.![]() |
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