#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1.0);
const double eps = 1e-7;
inline bool iszero(const double x) { return fabs(x) < eps; }
double gao(double a, double b, double d) {
  if (iszero(d)) return a * b;
  if (iszero(2 * d - PI)) return b * b;
  if (b * (1 + cos(d)) <= a * sin(d)) return b * b / sin(d);
  return a * b -
         (a * a + b * b - 2 * a * b * sin(d)) * (1 - cos(d)) / sin(2 * d);
}
int main() {
  double a, b, d;
  scanf("%lf%lf%lf", &a, &b, &d);
  d *= PI / 180;
  d = min(d, PI - d);
  if (a < b) swap(a, b);
  printf("%.16lf\n", gao(a, b, d));
  return 0;
}
