Time Limit: 1000ms
Memory Limit: 65536kb
DescriptionFANGHUA Garden is known as one of the "Top Ten Scenery" in WC(West Campus) of USTC.
To calculate the circumference of a lake seems to be an hard task - provided you do not know its exact shape and parameters. But what if you do?
Let's assume the lake in our FANGHUA Garden to be just a circle to make programmers' lives more beautiful.
To calculate the circumference of a circle seems to be an easy task - provided you know its diameter. But what if you don't?
You are given the cartesian coordinates of three non-collinear points in the plane. Your job is to calculate the circumference of the unique circle that intersects all three points.
InputThe input file will contain one or more test cases. Each test case consists of one line containing six real numbers x1,y1,x2,y2,x3,y3, representing the coordinates of the three points. The diameter of the circle determined by the three points will never exceed a million. Input is terminated by end of file.
OutputFor each test case, print one line containing one real number telling the circumference of the circle determined by the three points. The circumference is to be printed accurately rounded to two decimals. The value of PI is approximately 3.141592653589793.
0.0 -0.5 0.5 0.0 0.0 0.5 0.0 0.0 0.0 1.0 1.0 1.0 5.0 5.0 5.0 7.0 4.0 6.0 0.0 0.0 -1.0 7.0 7.0 7.0 50.0 50.0 50.0 70.0 40.0 60.0 0.0 0.0 10.0 0.0 20.0 1.0 0.0 -500000.0 500000.0 0.0 0.0 500000.0
3.14 4.44 6.28 31.42 62.83 632.24 3141592.65