#include <cmath>
#include <cstdio>
using namespace std;


int main()
{
	const double pi = std::acos(-1);
	int t, r, x;
	scanf("%d", &t);
	while (t--) {
		scanf("%d%d", &r, &x);
		double a = pi * x / 180;
		printf("%.7lf\n", r*sin(a)/(sin(a)*sin(a)+cos(a)));
	}
	return 0;
}