#include <bits/stdc++.h>
using namespace std;
int main() {
  double za, zb, zc;
  scanf("%lf%lf%lf", &za, &zb, &zc);
  if (zc > 90.0) {
    zc = 180.0 - zc;
  }
  if (za < zb) {
    swap(za, zb);
  }
  if (zc == 90.0) {
    printf("%lf\n", zb * zb);
    return 0;
  }
  zc /= 180.0;
  zc *= 3.14159265358979323846264338327950288;
  if ((1.0 + cos(zc)) / za < (sin(zc)) / zb) {
    printf("%lf\n", zb * zb * (1.0 / sin(zc)));
  } else {
    double pl = (za + zb) * sin(zc) / (1.0 + cos(zc) + sin(zc));
    double x = (za - pl) / (1 + cos(zc) - sin(zc));
    double y = (zb - pl) / (1 + cos(zc) - sin(zc));
    printf("%lf\n", za * zb - (x * x + y * y) * cos(zc) * sin(zc));
  }
}
