#include <cstdio>
#include <cmath>
using namespace std;
#define eps 1e-8
#define PI 2*acos(0)

int main()
{
  double a,b,th;
  while(scanf("%lf%lf%lf",&a,&b,&th),a+b+th>eps) {
    double c=sqrt(a*a+b*b-2*a*b*cos(th*PI/180));
    printf("%.3lf\n",c);
  }
}