名校
解题方法
1 . 如图,正方形
,
、
分别是
、
的中点,
是
的中点,沿
、
及
把这个正方形折成一个四面体,使
、
、
三点重合,重合后的点记为
,
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/e2f71e1b-90e1-488d-9860-82b3ef345693.png?resizew=303)
(1)求证:
所在平面;
(2)若正方形的边长为
,求四面体
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2ac787c642466044d50f89d5dac41da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7af9a10717d214e599ee121de74bf451.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aa7a689d8c7a11bc48ef98d9415c1968.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34c157ff302a881c17514534903c575f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fda40d4d62aa28f9e5f877bbea5ce511.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/011ae6cb0cf49f6d3d19b485dc1cfc22.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/86fda993d38532293724009685288b72.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a12119eba9da5c32568de5832ff04c4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/23/e2f71e1b-90e1-488d-9860-82b3ef345693.png?resizew=303)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03b00891cc76ea6741f657c16ba7a1cb.png)
(2)若正方形的边长为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b1d77e654fa5de3e4e8389c898e4657.png)
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名校
解题方法
2 . 如图,在四棱锥P—ABCD中,底面ABCD是边长为2的正方形,PA
平面ABCD,E为PD的中点.
![](https://img.xkw.com/dksih/QBM/2020/7/29/2516212501741568/2516601502433280/STEM/dfa2a480db124fe9ac4a7f5d1e22b2c2.png?resizew=199)
(1)证明:
平面
;
(2)若三棱锥C—ADE的体积为
,求PC与底面所成角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1633988fd62a652de726ee92a917b52d.png)
![](https://img.xkw.com/dksih/QBM/2020/7/29/2516212501741568/2516601502433280/STEM/dfa2a480db124fe9ac4a7f5d1e22b2c2.png?resizew=199)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9aa69a2247ad4d5231aa361349b12f97.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46e2da608b66c9aee03e2503388ba4fd.png)
(2)若三棱锥C—ADE的体积为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24c14ff9b66f21c05e52dc3c8908c2df.png)
您最近一年使用:0次
2020-07-29更新
|
1187次组卷
|
3卷引用:湖南省张家界市2019-2020学年高一下学期期末数学试题
3 . 如图,
是边长为3的等边三角形,四边形
为正方形,平面
平面
.点
、
分别为
、
上的点,且
,点
为
上的一点,且
.
![](https://img.xkw.com/dksih/QBM/2018/4/14/1923763909844992/1924617081028608/STEM/3e511052972e4bee95ecb477466beb82.png?resizew=178)
(Ⅰ)当
时,求证:
平面
;
(Ⅱ)当
时,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c6e2903ff33266528a7902ad51cf8d75.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0629ce42392a7fe9be21d25c39c3e64.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85774242bc1d990b56afd9f993f58cf8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0fbb1e062a1d59ed02ee1337fb562c24.png)
![](https://img.xkw.com/dksih/QBM/2018/4/14/1923763909844992/1924617081028608/STEM/3e511052972e4bee95ecb477466beb82.png?resizew=178)
(Ⅰ)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/73b3cf0f585938ede9eca890a6eb326d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/875d9827a6f048d6f577b794446b930b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b03428a8f91a5674cb8f54766c165f7e.png)
(Ⅱ)当
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ce1335e489c2b0835d7e16ea765e1e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/89151b3418437067124ede7499455d15.png)
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