#include <bits/stdc++.h>
double n, m, a, p, s, t, ans, pi = acos(-1.);
int main() {
  scanf("%lf%lf%lf", &n, &m, &a);
  if (n > m) t = n, n = m, m = t;
  if (a == 90)
    ans = n * n;
  else {
    ans = n * m, n /= 2, m /= 2, a > 90 ? a = 180 - a : a, a *= pi / 180,
    p = (pi - a) / 2;
    s = n - m / tan(p), ans -= s * s * tan(a), t = m - n / tan(p),
    ans -= t * t * tan(a);
    if (s < 0) ans = (n / tan(p) + n / tan(a)) * n * 4;
  }
  printf("%.9lf\n", ans);
  return 0;
}
