Geometry Paradox#1043
In the picture below you can see two small circles touching each other externally. The larger circle is positioned so that it touches both of the smaller circles, which are inside it. The chord of the larger circle is a common tangent to the two small circles with radii r_1 and r_2. The centers of all three circles are collinear. You are given the values of the radii r_1 and r_2, or the value of the chord . You must compute the area of the part of the larger circle marked in gray in the picture. If the given information is not sufficient to uniquely determine this area, output the message Impossible.
The first line contains the number of test cases (n \leq 100). Each of the next lines contains one input set.
Each input set contains either one or two integers. If it contains one integer, it is the value of ; if it contains two integers, these are the values of r_1 and r_2. All input numbers do not exceed .
For each input set, output one line. This line should contain the area of the gray part if the input is sufficient to determine it; otherwise, output a single word Impossible. Print the area with four digits after the decimal point.
Example 1