名校
解题方法
1 . 棱长为6的正方体内有一个棱长为a的正四面体,且该四面体可以在正方体内任意转动,则a的最大值为______
您最近一年使用:0次
2021-11-23更新
|
717次组卷
|
8卷引用:2019年全国高中数学联赛广西壮族自治区预赛
名校
2 . 如图,在正三棱柱
,(底面为正三角形的直三棱柱称为正三楼柱)中,
,
,
,
分别是棱
,
的中点,
为棱
上的动点,则
的周长的最小值为______ .
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/42d3a82b8e587ee890467835bc4e854c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fcd0ced286a0fbc7e4862f8147264277.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f7e8dd831f4edc711c0f7d5f078f625.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3634979dfcebf857b20874dd320d80b3.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/2/23/ceb7efbf-5ca2-4f54-92e9-2d12d4794732.png?resizew=158)
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2020-01-06更新
|
732次组卷
|
5卷引用:2018年全国高中数学联赛广西壮族自治区预赛
2018年全国高中数学联赛广西壮族自治区预赛(已下线)【新东方】杭州高二数学试卷236山西省太原市第五中学2019-2020学年高二10月阶段性检测数学(理)试题山西省太原市第五中学2019-2020学年高二10月阶段性检测数学(文)试题(已下线)第19讲 空间几何体概念
名校
解题方法
3 . 如图,已知平面
平面
,四边形
是正方形,四边形
是菱形,且
,点
分别为边
的中点,点
是线段
上的动点.
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638704566247424/1656268033253376/STEM/cef19feb86ea43e99d354edbbc3b725c.png?resizew=236)
(1)求证:
平面
;
(2)求三棱锥
的体积的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c674dc5024374f53920947c4cf4baf11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2dde327febef2331a4766a79b433cc02.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/46f611d0a0894890a13e08135c1b887d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9c0f067a2a348ceb24a408f82992eab8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/00bc67cc4eb17a62a39d9105ca763a6c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac047e91852b91af639feec23a9598b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/85c4bdfb0db1e31e8459df1d15f9ab55.png)
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638704566247424/1656268033253376/STEM/cef19feb86ea43e99d354edbbc3b725c.png?resizew=236)
(1)求证:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d07d16fc91aa960b67ba4b474de8a62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bc46688d8723cf2003fc25890265200.png)
(2)求三棱锥
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/350b7afa86146fb39d1fcd456c862b49.png)
您最近一年使用:0次
2017-04-01更新
|
878次组卷
|
3卷引用:2017届广西陆川县中学高三下学期知识竞赛文数试卷
4 . 某几何体的三视图如图所示,那么该几何体的体积是
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638704566247424/1656268032958464/STEM/b1fef09888424be593aae49fdb04699d.png?resizew=173)
![](https://img.xkw.com/dksih/QBM/2017/3/7/1638704566247424/1656268032958464/STEM/b1fef09888424be593aae49fdb04699d.png?resizew=173)
A.![]() | B.![]() | C.![]() | D.![]() |
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