import java.io.*;
import java.util.*;
 
public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
 
		short N = in.nextShort();
		double r, d, h_1, a, b;
		for (int i = 1; i <= N; i++){
			r = in.nextDouble();
			d = in.nextDouble();
			h_1 = in.nextDouble();
			out.print("Case " + i + ": ");
			a = Math.asin((r - h_1) / r) - Math.asin((r - d) / r);
			if (a == 0) out.format("%.4f%n", h_1);
			else{
				b = 2 * Math.sqrt(r*r - (r - d) * (r - d)) + h_1 / Math.sin(a);
				out.format("%.4f%n", b * Math.sin(a));
			}
		}
 
		out.flush();
	}
}

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5
94 21 12
23 9 8
5 4 3
2 2 1
43 26 20