已知三棱锥
如图
的展开图如图2,其中四边形ABCD为边长等于
的正方形,
和
均为正三角形.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/3bb221c8-cc0a-435b-a1ee-f6de9fc43421.png?resizew=322)
(1)证明:平面
平面ABC;
(2)若M是PC的中点,点N在线段PA上,且满足
,求直线MN与平面PAB所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/620d4a792615ce49b67a77fa507c102e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cdcf8a317ccc87a1bf8e17852fddbe29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e742966e3711cfa53dce04022acf4bcc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6830ebecddbd9759be626289c408e4f3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/3bb221c8-cc0a-435b-a1ee-f6de9fc43421.png?resizew=322)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
(2)若M是PC的中点,点N在线段PA上,且满足
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56a3f68ef76871ba5d28e2a9402dc446.png)
更新时间:2019-12-16 15:32:46
|
相似题推荐
解答题-证明题
|
较易
(0.85)
名校
解题方法
【推荐1】在边长为6的等边
(如图甲)中,已知点A,B分别为
的中点,现将
沿直线
翻折,使点P在底面
的射影刚好为对角线
与
的交点H,连接
得到四棱锥
(如图乙).
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/d1d61b73-922f-4ce1-a0a9-2a235ba8deae.png?resizew=290)
(1)求证:平面
平面
.
(2)求四棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/177678001b2ccde1db8f57fa5e017002.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fb46aaae98bce8e66848e09c2c1cdbd4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2205cffebf8c4d5f81d15ed7b85c8936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b319212a7e7528b053e1c7097e966.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/24e7344dca1e40bf072371ddd5640111.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/3/1/d1d61b73-922f-4ce1-a0a9-2a235ba8deae.png?resizew=290)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/93edc7bb513f40a89173121c8570cd65.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0628681907ac8d7fdb94d8bc1b15feb9.png)
(2)求四棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0585b6c0f156eecf9662b9846d4eb693.png)
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【推荐2】如图,在四棱锥
中,四边形
为正方形,
平面
,点
是棱
的中点,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/3/c7c39c38-7f59-470a-b24c-76718f645d80.png?resizew=209)
(1)若
,证明:平面
平面
;
(2)若三棱锥
的体积为
求三棱锥
的体积.
![](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/5a1b49f64e0065edad868b25e9fcada3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2671ccd5af7fa8b2cdd41774d2e81ce9.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/11/3/c7c39c38-7f59-470a-b24c-76718f645d80.png?resizew=209)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8cbeede118c407a800b05757b9a1393e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8513f84fd057f113d54797d38624a752.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e7b7c83470489253394bd288d7c920df.png)
(2)若三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/371684bec69936238bb9d162431b7e17.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d599cb4a589f90b0205f24c2e1fa021e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e749d4e67d0a2dcb44829c79dd58c22.png)
您最近一年使用:0次
解答题-问答题
|
较易
(0.85)
【推荐3】回答问题(画图并说明理由).
(1)长方体与平行六面体的区别是什么?怎么判断一个四棱柱是长方体?
(2)指出长方体中对角面与底面所成的二面角及其平面角;对角面与侧面所成的二面角及其平面角;两个对角面所成的二面角及其平面角.
(3)长方体中哪些二面角构成直二面角?正四棱柱呢?正方体呢?
(4)为什么说长方体中侧面与底面一定是垂直的?
(5)长方体中侧棱与底面内的每一条直线是什么关系?两条侧棱有什么关系?为什么?
(6)长方体中平行于侧棱的直线与底面内的每一条直线是什么关系?长方体的上下两底中心连线与底面内的每一条直线是什么关系?为什么?
(7)利用长方体模型,把关于垂直关系的判定定理与性质定理所表示的图形找出来,并用文字及符号表达.
(1)长方体与平行六面体的区别是什么?怎么判断一个四棱柱是长方体?
(2)指出长方体中对角面与底面所成的二面角及其平面角;对角面与侧面所成的二面角及其平面角;两个对角面所成的二面角及其平面角.
(3)长方体中哪些二面角构成直二面角?正四棱柱呢?正方体呢?
(4)为什么说长方体中侧面与底面一定是垂直的?
(5)长方体中侧棱与底面内的每一条直线是什么关系?两条侧棱有什么关系?为什么?
(6)长方体中平行于侧棱的直线与底面内的每一条直线是什么关系?长方体的上下两底中心连线与底面内的每一条直线是什么关系?为什么?
(7)利用长方体模型,把关于垂直关系的判定定理与性质定理所表示的图形找出来,并用文字及符号表达.
您最近一年使用:0次
解答题-问答题
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较易
(0.85)
解题方法
【推荐1】已知正方形
的边长为
,
为两条对角线的交点,如图所示,将Rt△BED沿BD所在的直线折起,使得点E移至点C,满足
.
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712413310828544/2714298242097152/STEM/fc4184ee-8031-4e69-8a0e-efa5bee11cf4.png?resizew=316)
(1)求四面体
的体积
;
(2)请计算:
①直线
与
所成角的大小;
②直线
与平面
所成的角的大小.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e1d70676406f26d339465fe3473c0c05.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://img.xkw.com/dksih/QBM/2021/5/2/2712413310828544/2714298242097152/STEM/fc4184ee-8031-4e69-8a0e-efa5bee11cf4.png?resizew=316)
(1)求四面体
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
(2)请计算:
①直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
②直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b4eb7e9ad5486cf1c5e506b20c5469e8.png)
您最近一年使用:0次
解答题-问答题
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较易
(0.85)
名校
【推荐2】如图,在三棱锥P﹣ABC中,
和
都为等腰直角三角形,
,
,M为AC的中点,且
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/0595e35e-43e4-42f8-be4b-7d9516ce0f68.png?resizew=180)
(1)求二面角P﹣AB﹣C的大小;
(2)求直线PM与平面PBC所成角的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/53502463cc76201000e02df314e58769.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83640592853a53872d7af69c0cffc1bb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/36c4559d27e3905980d1a4f1856f07de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d342fe7902463b0354d9dcae71ef809.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/7/0595e35e-43e4-42f8-be4b-7d9516ce0f68.png?resizew=180)
(1)求二面角P﹣AB﹣C的大小;
(2)求直线PM与平面PBC所成角的正弦值.
您最近一年使用:0次