#include <bits/stdc++.h>
using namespace std;
int main() {
  int aa, bb, al;
  double alpha, beta, gama, O, a, b, c, x, y, z, t, ret, S, q;
  while (scanf("%d %d %d", &aa, &bb, &al) == 3) {
    a = aa;
    b = bb;
    ret = a * b;
    if (al == 0 || al == 180) {
      printf("%.13lf\n", ret);
      continue;
    }
    if (al > 90) al = 180 - al;
    alpha = 1.0 * al / 90 * acos(0);
    if (a > b) swap(a, b);
    if (alpha < 2.0 * atan(1.0 * a / b))
      ret = (2.0 * a * b * sin(alpha) + (a * a + b * b) * (cos(alpha) - 1)) /
            (sin(2.0 * alpha));
    else
      ret = a * a / (sin(alpha));
    printf("%.13lf\n", ret);
  }
  return 0;
}
