The Circumference of the Circle#1045
Calculating the circumference of a circle is a simple task if you know its diameter. But what if you don't?
You are given the Cartesian coordinates of three non-collinear points on a plane.
Your task is to calculate the circumference of the circle passing through these three points.
The input consists of several test cases. Each test case consists of a single line containing six real numbers x_1, y_1, x_2, y_2, x_3, y_3 representing the coordinates of the three points. It is guaranteed that the diameter of the circle defined by these three points does not exceed .
For each test case, print on a separate line the circumference of the circle defined by these three points. Print the circumference with 2 decimal digits.
Example 1