import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n=sc.nextInt(); while(n-->0){ double x1=sc.nextDouble(), y1=sc.nextDouble(),x2=sc.nextDouble(),y2 =sc.nextDouble(); double s1=Math.sqrt(x1*x1+y1*y1); double s2=Math.sqrt(x2*x2+y2*y2); double s3=Math.sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2)); double p=(s1+s2+s3)/2; double area=Math.sqrt(p*(p-s1)*(p-s2)*(p-s3)); // area=1/2*s1*s2*sin@ //sin@=area*2/(s1*s2) System.out.printf("%.2f\n",Math.asin(area*2/s1/s2)/Math.PI*180); } } }
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