#include <bits/stdc++.h>
using namespace std;
long long ll, i, j, cl, ss, ce, a[221456], b[212145], c, d;
double x, m, n, s, t, k, l, y, z;
string p, r, q;
map<long long, bool> bb;
int main() {
  cin >> n >> m >> x;
  if (x > 90) x = 180.0 - x;
  if (n > m) swap(n, m);
  z = atan(n / m) * 2.0;
  y = x * 3.14159265359 / 180.0;
  x = x * 3.14159265359 / 360.0;
  if (y >= z) {
    s = n * n / sin(y);
    printf("%.7lf", s);
    return 0;
  }
  s = m * n;
  k = m - n * tan(x);
  l = k * k * tan(y);
  s -= l / 4.0;
  k = n - m * tan(x);
  l = k * k * tan(y);
  s -= l / 4.0;
  printf("%.7lf", s);
  return 0;
}
