Type: Default 100ms 64MiB

Mibbp的几何题

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题目背景

为了防止刷视频智力退化,请完成以下初中数学题

题目描述

如图所示,圆AAAA点为圆心,圆BBBB点为圆心,两圆半径均为xx,且圆心AA到圆心BB的距离为xx,两圆重合处有一内接等腰三角形ΔCDE\Delta CDECC为两圆交接点,角DCE=30°\angle DCE = 30\degree,求ΔCDE\Delta CDE面积,π=3.1415926535897931\pi = 3.1415926535897931

image

输入

输入一个值表示x

输出

输出ΔCDE\Delta CDE面积,结果保留10位小数

样例

3
4.5000000000

数据范围

  • 1x1061 \leq x \leq 10^6