23-24高三上·北京西城·期末
名校
1 . 如图,水平地面上有一正六边形地块
,设计师规划在正六边形的顶点处矗立六根与地面垂直的柱子,用以固定一块平板式太阳能电池板
.若其中三根柱子
,
,
的高度依次为
,则另外三根柱子的高度之和为( )
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9165d9bfbb0f0d19eb482c2a4c1b29b7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6f1cd65c246e928ee9f3c79710648fe.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2777840758e70e7dbbc18cef8f3d6d2b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e0a851907ada2ac2c3c4880a6736d28a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d88bf46ad08f9677c37eed1d0369329.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9e5e3262600b50c112924b5cc14194e4.png)
A.47m | B.48m | C.49m | D.50m |
您最近一年使用:0次
2024-01-19更新
|
699次组卷
|
3卷引用:北京市西城区2024届高三上学期期末数学试题
2 . 现代几何学用曲率概念描述几何体的弯曲程度.约定:多面体在每个顶点处的曲率等于
减去该点处所有面角之和(多面体每个侧面的内角叫做多面体的面角),一个多面体的总曲率等于该多面体各顶点处的曲率之和.例如:正方体在每个顶点处有3个面角,每个面角的大小是
,所以正方体在各顶点处的曲率为
.按照以上约定,四棱锥的总曲率为__________ ;若正十二面体(图1)和正二十面体(图2)的总曲率分别为
和
,则![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2fa9cb6397796d85c5089709797b943.png)
__________ 0(填“>”,“<”或者“=”).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35e2d7c958e99bcd9d7f251c19ee3544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d49f8a63ddbca52039fa9ab44cda6b29.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/da15940a9c6bbbdb34b18b514e98ba31.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/25f64fa38725c136504f723019a18dc5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e93fa313adc4ac7608ba9449fd755212.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d2fa9cb6397796d85c5089709797b943.png)
![](https://img.xkw.com/dksih/QBM/editorImg/2023/1/6/546e186d-d223-48c4-ab66-31cc175434bd.png?resizew=256)
您最近一年使用:0次
3 . 连接空间几何体上的某两点的直线,如果把该几何体绕此直线旋转角
,使该几何体与自身重合,那么称这条直线为该几何体的旋转轴.如图,八面体的每一个面都是正三角形,并且4个顶点
,
,
,
在同一平面内.则这个八面体的旋转轴共有( )
![](https://img.xkw.com/dksih/QBM/2020/9/13/2549127942774784/2577841017626624/STEM/a937553d-2d42-47e0-b6ca-8fd8b56e8a3a.png?resizew=201)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2c54ce139ae5d63691cac8a1ce5bbfe4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://img.xkw.com/dksih/QBM/2020/9/13/2549127942774784/2577841017626624/STEM/a937553d-2d42-47e0-b6ca-8fd8b56e8a3a.png?resizew=201)
A.7条 | B.9条 | C.13条 | D.14条 |
您最近一年使用:0次