如图,在四棱锥
中,
平面
,
∥
,
.
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/0d7a4fd0f22e4a1a91529185c3fc8891.png)
(1)当正视方向与向量
的方向相同时,画出四棱锥
的正视图(要求标出尺寸,并写出演算过程);
(2)求三棱锥
的体积.
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/be9c01e1d220452fb2e4f768e91f89fc.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/f91e03fc6f31400b9ac3140c300b141b.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/a556f185f609440d8bc1a829b228c569.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/948c4f2e9da441d0a51f6ac2b90196d5.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/9f92d135b4d546acba860727c3f831bb.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/525a05067a5246cd81b4fc6819e45a77.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/0d7a4fd0f22e4a1a91529185c3fc8891.png)
(1)当正视方向与向量
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/28d74e081ceb4074a322a4e7eb4a5bb6.png)
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/be9c01e1d220452fb2e4f768e91f89fc.png)
(2)求三棱锥
![](https://img.xkw.com/dksih/QBM/2016/1/5/1572418545074176/1572418551169024/STEM/4fbbe13f61fe49e48728e122dc7f3a49.png)
更新时间:2016-12-03 23:56:38
|
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解答题-问答题
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适中
(0.65)
名校
【推荐1】在三棱锥
中,已知平面
平面
,
是底面
最长的边,三棱锥
的三视图如图1所示,其中侧视图和俯视图均为直角三角形;
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/8d5a364d-6cc8-4f06-a8fe-6ac7eda18012.png?resizew=302)
(1)请在图2中,用斜二测画法,把三棱锥
的直观图补充完整(其中点
在
平面内),并指出三棱锥
的哪些面是直角三角形;
(2)求点
到面
的距离;
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/78a3fd5284e160896f07ce367645fd04.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0faed94a64b2dcfc6801b4fca0f16675.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/12/1/8d5a364d-6cc8-4f06-a8fe-6ac7eda18012.png?resizew=302)
(1)请在图2中,用斜二测画法,把三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7d96461d2b3421aed548b754637ca8a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/63397cda22cb1fad59cf966dfb588643.png)
(2)求点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1e582d73b96ba649378379c3074d506d.png)
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【推荐2】如图是一建筑物的三视图(单位:
),现需将其外壁用油漆粉刷一遍,已知每平方米用漆
,问需要油漆多少千克?(无需求近似值)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e15e00f40396e914d1d9955bd7785f1f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5cb101ca30d55fddae396bafc281d2d6.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2022/9/27/58849f30-3f13-4a4e-abf8-2fae2850c150.png?resizew=160)
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解答题-证明题
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适中
(0.65)
解题方法
【推荐1】如图,在三棱柱
中,
,
分别是
的中点,设
到平面
的距离为
,
到平面
的距离为
.
![](https://img.xkw.com/dksih/QBM/2021/9/1/2798590737088512/2802471652900864/STEM/1387fe16-f223-42fa-8559-d6b2120075c5.png?resizew=250)
(1)求证:
;
(2)若三棱柱
是直三棱柱,
,求
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/047dc9795efa99b6fb9fdf9778085dab.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e4f1a5d2d96354bfee8e28abc15b16e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/595381461515f47bb4796ee2934defa4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/192cbe130dd9ddbe4bfcf56d51450936.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e8cca4f1e9b918c89399a2a0024a60f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://img.xkw.com/dksih/QBM/2021/9/1/2798590737088512/2802471652900864/STEM/1387fe16-f223-42fa-8559-d6b2120075c5.png?resizew=250)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7920d2550a6af7df3db60a33fe02c53b.png)
(2)若三棱柱
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f6657ad109972ea7a5246b4d8190ec.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0be44077d42cfffece905b1af13e000.png)
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解题方法
【推荐2】如图,三棱柱
中,
是
的中点,
.
平面
;
(2)若
,点
到平面
的距离为
,求三棱锥
的体积.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/acbc1149fd821884d6c19c1a35f3b991.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a5ed4b84d38a6c0916bc4ac92f011e8e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/565133e91e3ace2b2187cfc6f1db5be6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bef5239ddbb0972700ce01daf9ee7cf.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/21ea52361458ce2e49ed0fe99d8e6c02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/97c01fdc7bc471af0b264a04aef0823e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d9a8181f7a7fe7f3fac872ce9534f15.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8d5989c84e320b504511f23eeb6e7357.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0b83c278a81df62b7a9cc8f3789b466b.png)
您最近一年使用:0次