#include <bits/stdc++.h>
using namespace std;
double w, h, al;
double th;
int main() {
  scanf("%lf%lf%lf", &w, &h, &al);
  if (w < h) {
    double f = w;
    w = h;
    h = f;
  }
  if (al > 90) al = 180 - al;
  th = atan(h / w);
  al = al * 3.14159265359 / 180;
  if (al >= 2 * th) {
    printf("%f\n", h * h / sin(al));
    return 0;
  }
  double d = w / 2 - h * tan(al / 2) / 2;
  double e = h / 2 - w * tan(al / 2) / 2;
  double ans = w * h;
  ans -= d * d * tan(al);
  ans -= e * e * tan(al);
  printf("%.8f\n", ans);
}
