private static void Main()
{
var numberOfCases = int.Parse(Console.ReadLine());
for (int c = 0; c < numberOfCases; c++)
{
double[] line = Array.ConvertAll(Console.ReadLine().Split(), double.Parse);
Console.WriteLine(QUADAREA.Solve(line[0], line[1], line[2], line[3]));
}
}
private static void Main()
{
var output = new StringBuilder();
int remainingTestCases = int.Parse(Console.ReadLine());
while (remainingTestCases-- > 0)
{
double[] line = Array.ConvertAll(Console.ReadLine().Split(), double.Parse);
output.AppendLine(
QUADAREA.Solve(line[0], line[1], line[2], line[3]).ToString());
}
Console.Write(output);
}
