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设△ABC的三边长分别为a、b、c,△ABC的面积为S,内切圆半径为,则.类比这...
设△ABC的三边长分别为a、b、c,△ABC的面积为S,内切圆半径为,则
![manfen5.com 满分网](http://img.manfen5.com/res/GZSX/web/STSource/20131101222934305405854/SYS201311012229343054058012_ST/0.png)
.类比这个结论可知:四面体A-BCD的四个面分别为S
1、S
2、S
3、S
4,内切球半径为R,四面体A-BCD的体积为V,则R=
.
考点分析:
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