#include <bits/stdc++.h>
const long long INF = 1000000000;
using namespace std;
int main() {
  double h, w;
  double a;
  while (scanf("%lf%lf%lf", &w, &h, &a) != EOF) {
    if (h > w) swap(h, w);
    if (a > 90) a = 180 - a;
    a = a * 3.1415926535897932 / 180.0;
    if (a < atan(h / w) * 2) {
      double x = 0.5 * w - 0.5 * h * tan(a / 2);
      double y = 0.5 * h - 0.5 * w * tan(a / 2);
      double ans = h * w - x * x * tan(a) - y * y * tan(a);
      printf("%.8lf\n", ans);
    } else
      printf("%.8lf\n", h * h / sin(a));
  }
  return 0;
}
