杭赛.Triangle(数学推导）

Triangle

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 0    Accepted Submission(s): 0

Problem Description

This is a simple question, give you a triangle, please divide the triangle into two parts with a segment. These two parts should have the same area, and the segment should be as short as possible. Please calculate the length of the segment.

 

Input

The first line of the input is the number T(T<=100), which is the number of cases followed. For each test case, the only line contains space-separated integers x1, y1, x2, y2, x3, y3,the coordinates of triangle endpoint. The absolute value of all the coordinates will not be more than 10⁹.

 

Output

For each test case, output only one line, containing the length of segment only. Your answer should be rounded to 4 digits after the decimal point.

 

Sample Input

1
0 0 10 0 0 10

 

Sample Output

6.4359

 

最短分割线定理：

Z^2 = |a | * |b| - a * b