2023高三·全国·专题练习
解题方法
1 . 北京大兴国际机场的显著特点之一是各种弯曲空间的运用,在数学上用曲率刻画空间弯曲性.规定:多面体的顶点的曲率等于
与多面体在该点的面角之和的差(多面体的面的内角叫做多面体的面角,角度用弧度制),多面体面上非顶点的曲率均为零,多面体的总曲率等于该多面体各顶点的曲率之和.例如:正四面体在每个顶点有
个面角,每个面角是
,所以正四面体在每个顶点的曲率为
,故其总曲率为
.给出下列三个结论:
![](https://img.xkw.com/dksih/QBM/2023/6/16/3260674968248320/3260854239141888/STEM/79002e99bec346b2bc124025082f81ba.png?resizew=264)
①正方体在每个顶点的曲率均为
;
②任意四棱锥的总曲率均为
;
③若某类多面体的顶点数
,棱数
,面数
满足
,则该类多面体的总曲率是常数.
其中,所有正确的结论是____________ (填写序号).
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35e2d7c958e99bcd9d7f251c19ee3544.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5ca7d1107389675d32b56ec097464c14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ac1a63ab608517bb10aa036783dfb51f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ba7b2dd83fcacead6b6c7733503dfcee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20b3a91ccf6028608cd03df7072f6536.png)
![](https://img.xkw.com/dksih/QBM/2023/6/16/3260674968248320/3260854239141888/STEM/79002e99bec346b2bc124025082f81ba.png?resizew=264)
①正方体在每个顶点的曲率均为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d49f8a63ddbca52039fa9ab44cda6b29.png)
②任意四棱锥的总曲率均为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/20b3a91ccf6028608cd03df7072f6536.png)
③若某类多面体的顶点数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/be54e84508decfcce6d2fcbe6c8c1a92.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0c91c4472879d107d42da5b07fab777e.png)
其中,所有正确的结论是
您最近一年使用:0次