#include <bits/stdc++.h>
using namespace std;
double w, h;
int z;
int main() {
  int W, H;
  scanf("%d%d%d", &W, &H, &z);
  w = W, h = H;
  if (w < h) swap(w, h);
  if (z > 90) z = 180 - z;
  double alpha = z * acos(-1) / 180;
  if (alpha < 2 * atan2(h, w) - 1e-10) {
    double a = cos(alpha), b = sin(alpha);
    printf("%.9f\n",
           (w * h - b * (h * h + w * w - 2 * w * h * b) / (2 * a * (1 + a))));
  } else
    printf("%.9f\n", (h * h / sin(alpha)));
  return 0;
}
