解题方法
1 . 如图,在三棱锥
中,
,
,
.
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953169238556672/2957121693130752/STEM/42721b43-0eb3-4219-84ea-dd90368e4140.png?resizew=178)
(1)求三棱锥
的体积和表面积
(2)若E、F分别为PA、PB的中点,求证
面EFC.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a9b8e7befcb7881c294070175b1a554.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b5064f5ce5ac8428e277fd578da84ec6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d715e6b470395136a6c4215dbe6ff82e.png)
![](https://img.xkw.com/dksih/QBM/2022/4/7/2953169238556672/2957121693130752/STEM/42721b43-0eb3-4219-84ea-dd90368e4140.png?resizew=178)
(1)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
(2)若E、F分别为PA、PB的中点,求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ea2cfa68b1900da8c1a71dd832872689.png)
您最近一年使用:0次
2022-04-13更新
|
283次组卷
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2卷引用:重庆市酉阳县第三中学校2021-2022学年高一下学期第二次月考数学试题
解题方法
2 . 如图,在平面四边形APBC中,
,
,
,
.将
沿AB折起得到三棱锥
,使得
.
![](https://img.xkw.com/dksih/QBM/2022/5/13/2978782097760256/2980732350521344/STEM/291c3cd1-a0a1-48bb-8910-9d8fb9decf47.png?resizew=302)
(1)求证:
平面ABC;
(2)若点E在棱
上,
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fd108abaf2b7fc1d0239b28afcf4ae6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a606499df4459e5fbd6021c61a805359.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b15b82151bff7cc0238d2034a6129f0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ec33fd6af9f2d43627d42061e5abbd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad34a693f8fae0c32f2b51d4a61b1de.png)
![](https://img.xkw.com/dksih/QBM/2022/5/13/2978782097760256/2980732350521344/STEM/291c3cd1-a0a1-48bb-8910-9d8fb9decf47.png?resizew=302)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f88842cdaf98f1603aa95f1a6fe1a16.png)
(2)若点E在棱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6ca15691dfea154b932004966f2fbca3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b05faa9dc3d99b201de1af0124e0dc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/51f73a0ca4e6c794242489066fddb6c5.png)
您最近一年使用:0次
2022-05-16更新
|
556次组卷
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3卷引用:重庆市酉阳土家族苗族自治县第三中学校2021-2022学年高一下学期第三次月考数学试题
3 . 如图,在三棱锥
中,平面
平面
,且
,
,
,
.点E、F分别为
上的点,满足
,点G为线段
中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/c2fbd0d1-3d41-47b2-91be-35c7848f0801.png?resizew=198)
(1)证明:平面
平面
;
(2)求
与平面
所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcf6dc837ae85207789b94d109c5c2eb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1134c8e3440abb6cd385af2c169037fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bd6a2b112facda441f4e34bf5c145fa.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/341e8dae00f6b2abc94199ccfd6cf180.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f65aff0abef2633a6c96690a43285d26.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ec451c43455189eae382b7709b3ae80e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/afe2686ad073830532a9895dbbbe0aee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/13/c2fbd0d1-3d41-47b2-91be-35c7848f0801.png?resizew=198)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a3d7090639341730951c1bc3c9b6164e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(2)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e72b2e1ff83e95df048745322982451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
您最近一年使用:0次
2022-05-16更新
|
603次组卷
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3卷引用:重庆市酉阳土家族苗族自治县第三中学校2021-2022学年高一下学期第三次月考数学试题