解题方法
1 . 用光线照射物体,在某个平面上得到的影子叫做物体的投影,照射光线叫做投影线,投影所在的平面叫做投影面.由平行光线形成的投影叫做平行投影,由点光源发出的光线形成的投影叫做中心投影.投影线垂直于投影面产生的平行投影叫做正投影,投影线不垂直于投影而产生的平行投影叫做斜投影.物体投影的形状、大小与它相对于投影面的位置和角度有关.如图所示,已知平行四边形
在平面
内的平行投影是四边形
.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/71cf6fa5-9cb4-4d8d-a907-fa7ccdcd6d3d.png?resizew=314)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/9fc4f21f-3f78-4976-887c-0642c3365737.png?resizew=314)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/462c058d-eb41-4d4a-ac0e-89fb806fef7a.png?resizew=314)
(1)若平行四边形
平行于投影面(如图
),求证:四边形
是平行四边形;
(2)在图
中作出平面
与平面
的交线(保留作图痕迹,不需要写出过程);
(3)如图
,已知四边形
和平行四边形
的面积分别为
,平面
与平面
的交线是直线
,且这个平行投影是正投影.设二面角
的平面角为
(
为锐角),猜想并写出角
的余弦值(用
表示),再给出证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d609847e2ff3d64e5a514582c3ead0e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/71cf6fa5-9cb4-4d8d-a907-fa7ccdcd6d3d.png?resizew=314)
图
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/9fc4f21f-3f78-4976-887c-0642c3365737.png?resizew=314)
图
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/15/462c058d-eb41-4d4a-ac0e-89fb806fef7a.png?resizew=314)
图
(1)若平行四边形
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bdaa19de263700a15fcf213d64a8cd57.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d609847e2ff3d64e5a514582c3ead0e.png)
(2)在图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
(3)如图
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0d609847e2ff3d64e5a514582c3ead0e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3637753af5ce86be9c23a9beb6b5067.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e170f206fdbbd834aad7580c727e2cc6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7021666155884a8aa345ed8eec3d2a01.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d3637753af5ce86be9c23a9beb6b5067.png)
您最近一年使用:0次
名校
2 . 如图,在三棱柱
中,
平面
为正三角形, 侧面
是边长为
的正方形,
为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/2803d4c7-4397-4140-a746-ececddd814d4.png?resizew=215)
(1)求证
平面
;
(2)求二面角
的余弦值;
(3)试判断直线
与平面
的位置关系,并加以证明.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be9ee7fff039524b6848147d14444b5e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d25e8fc3dda4f8b45491514b6e22a962.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dcaa21c6cc1086f121dbf9e39e52ec78.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab3e0dba5705e1d749cfb21ebbb2ed93.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/61128ab996360a038e6e64d82fcba004.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0dc5c9827dfd0be5a9c85962d6ccbfb1.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/29/2803d4c7-4397-4140-a746-ececddd814d4.png?resizew=215)
(1)求证
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6a22daf90ae241f084d526f7a6025926.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41104641f3e2260d00aeadf8fb8a078a.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/379c7b2495bdfcac49c1979bb14bcf5e.png)
(3)试判断直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/11ddc92d84d188c66b435664a7e7b5a4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/41104641f3e2260d00aeadf8fb8a078a.png)
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2020-01-13更新
|
604次组卷
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2卷引用:北京市西城区2019-2020学年高三上学期期末数学试题
3 . 如图正方体
的棱长为2,
平面
;
(2)证明:
平面
;
(3)求三棱锥
的体积;
(4)二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd98a2b9df67504e9f276e9a03d03432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc1c04946340198af69170d4ebd4b42.png)
(3)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab9e8d0969ba6da74d8b5b6c1ad993e6.png)
(4)二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cab6ad3d3e3064fa417a02dba02dbf04.png)
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4 . 如图,四棱锥
中,
平面
,过
的平面分别与棱
交于点M,N.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/e95dc946-c25c-4d15-a1b0-4b07fc31b4e8.png?resizew=155)
(1)求证:
;
(2)记二面角
的大小为
,求
的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/80c753cb1eb73fd8d136d00462970797.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9f4c3f9dd5d0343597a7f58a1989b537.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a632c970535e3dc49bb46519275882e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/03902478df1a55bc99703210bccab910.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b82fd2c740aea7423ecc2077ed899260.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/1/31/e95dc946-c25c-4d15-a1b0-4b07fc31b4e8.png?resizew=155)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a87e85906b2ee9c5d88d271b748ec33.png)
(2)记二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4e13c1dc9dee7eb7aed3d3ef41b2123a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c24095e409b025db711f14be783a406c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/aefd06c239145a2b6ae87a955aa51414.png)
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2024-01-17更新
|
489次组卷
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3卷引用:北京市海淀区2023-2024学年高二上学期期末练习数学试卷
5 . 如图,在直三棱柱
中,
.
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/8/77ad79b6-0906-4c6a-a511-0af51f8c90bc.png?resizew=142)
(1)证明:直线
平面
;
(2)求二面角
的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ae1b5a1a3f5cb44a771944e1534563b.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2024/2/8/77ad79b6-0906-4c6a-a511-0af51f8c90bc.png?resizew=142)
(1)证明:直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4560fa4ad459b58b723c74bd24e51ebf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9afac7c616bbb14e1ed428a3c507c7dc.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c7994f25559402687fa7f7d8a3966928.png)
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6 . 如图,从长、宽,高分别为
,
,
的长方体
中截去部分几何体后,所得几何体为三棱锥
.
的体积;
(2)证明:三棱锥
的每个面都是锐角三角形;
(3)直接写出一组
,
,
的值,使得二面角
是直二面角.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f8aa00ff754893ecaa673751fbec7933.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
(2)证明:三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/891579e7c231584a8e16b8eeff79888e.png)
(3)直接写出一组
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c94bb12cee76221e13f9ef955b0aab1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35c079889aea502b5783046f78728eb1.png)
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2023-07-10更新
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283次组卷
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3卷引用:北京市大兴区2022-2023学年高一下学期期末检测数学试题
北京市大兴区2022-2023学年高一下学期期末检测数学试题【北京专用】专题14立体几何与空间向量(第三部分)-高一下学期名校期末好题汇编(已下线)专题06 空间中点线面的位置关系6种常考题型归类(2) -期期末真题分类汇编(北京专用)
7 . 如图,正方体
的棱长为2.
平面
;
(2)证明:
平面
;
(3)求二面角
的正弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bd98a2b9df67504e9f276e9a03d03432.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7935fe3125f247b7bea4f065ce9ad985.png)
(2)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5a5928c98b341b16d4b5a5b931d2929d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6cc1c04946340198af69170d4ebd4b42.png)
(3)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cab6ad3d3e3064fa417a02dba02dbf04.png)
您最近一年使用:0次
2023-08-04更新
|
662次组卷
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4卷引用:北京市怀柔区2022-2023学年高一下学期期末数学试题
北京市怀柔区2022-2023学年高一下学期期末数学试题【北京专用】专题14立体几何与空间向量(第三部分)-高一下学期名校期末好题汇编(已下线)高一下学期期末模拟卷(范围:必修第二册全册)-同步题型分类归纳讲与练(人教A版2019必修第二册)(已下线)专题06 空间中点线面的位置关系6种常考题型归类(2) -期期末真题分类汇编(北京专用)
解题方法
8 . 如图,在长方体
中,
,
,点E为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/d174e08c-e63b-4b83-b2e6-575640f8dfb7.png?resizew=190)
(1)求证:AE⊥平面
;
(2)求平面
与平面
的夹角的余弦值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6e09725691ee7851f54c0dee86b2bf55.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/af0e44cb429eea46e7ee4320147192b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09d27bd71d79cb19eb554175e4ef0867.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/d174e08c-e63b-4b83-b2e6-575640f8dfb7.png?resizew=190)
(1)求证:AE⊥平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4755dc59cb5a03cd39879bc80fdbb9.png)
(2)求平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e4755dc59cb5a03cd39879bc80fdbb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/632f2bf1cd0435041fa04b01901d1c8c.png)
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解题方法
9 . 如图,在三棱柱
中,平面
平面
,侧面
是边长为2的正方形,
分别为
的中点.
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/44e29202-58ce-4e59-a9ae-6b55a7711348.png?resizew=199)
(1)证明:![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
面![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
(2)请再从下列三个条件中选择一个补充在题干中,完成题目所给的问题.
①直线
与平面
所成角的大小为
;②三棱锥
的体积为
;③
. 若选择条件___________.
求(i)求二面角
的余弦值;
(ii)求直线
与平面
的距离.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/91ba5715a95b8de18c637c12c3d30d7d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d12b92bb195943c794a3b3cf135d71a0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4ddef39ef9ed3da136c4ed8b5d28b73e.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/5/44e29202-58ce-4e59-a9ae-6b55a7711348.png?resizew=199)
(1)证明:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/638537c0a30676c73fea76c80e0f8bd0.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
(2)请再从下列三个条件中选择一个补充在题干中,完成题目所给的问题.
①直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e168672b47d7e64dc1b404f8882c7dcf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/15615de1a6df206dbd081251f676578e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8da67af246912670bac6dc860f301383.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4dac452fbb5ef6dd653e7fbbef639484.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ff4fcf607b0710d12aaabd17fd053d83.png)
求(i)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/34ecc467cf90f9f26cf6902af77427ca.png)
(ii)求直线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/49b50357a6545cae8348e3059312f520.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/72f0d0e78101fef36a75b70ac7e7cf5b.png)
您最近一年使用:0次
2023-01-03更新
|
893次组卷
|
3卷引用:北京市海淀实验中学2023届高三上学期期末数学试题
北京市海淀实验中学2023届高三上学期期末数学试题第八章立体几何初步章节验收测评卷-【精讲精练】2022-2023学年高一数学下学期同步精讲精练(人教A版2019必修第二册)(已下线)重难点突破02 利用传统方法求线线角、线面角、二面角与距离(四大题型)
名校
10 . 已知三棱锥
中,
.
(1)求证:平面
平面
;
(2)求二面角
的余弦值;
(3)若点M在线段
上,满足
,点N在线段
上,且
,求
的取值范围.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/181f49f169aa408109fbafdab077a891.png)
(1)求证:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6d077f6da8b2c00b152d4679aa2ed7f7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)求二面角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a438393ddfc7da1804baf4932442bb35.png)
(3)若点M在线段
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/48f3c9abbd78e9a6840ee5f30381daac.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f7cf1b9fa4914fe152dccc7da221b0fc.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2be49c37e30a3ced0364c3e74d8c687.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79498e1df1280868532f59ee8059a223.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c3dbfc9719c6646d58bda36dba623902.png)
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