#include <bits/stdc++.h>
using namespace std;
const int maxn = 300;
const double eps = 1e-8;
const double pi = acos(-1);
int dcmp(double x) {
  if (x > eps) return 1;
  return x < -eps ? -1 : 0;
}
struct Point {
  double x, y;
};
double cross(Point a, Point b, Point c) {
  return (a.x - c.x) * (b.y - c.y) - (b.x - c.x) * (a.y - c.y);
}
Point intersection(Point a, Point b, Point c, Point d) {
  Point p = a;
  double t = ((a.x - c.x) * (c.y - d.y) - (a.y - c.y) * (c.x - d.x)) /
             ((a.x - b.x) * (c.y - d.y) - (a.y - b.y) * (c.x - d.x));
  p.x += (b.x - a.x) * t;
  p.y += (b.y - a.y) * t;
  return p;
}
double PolygonArea(Point p[], int n) {
  if (n < 3) return 0.0;
  double s = p[0].y * (p[n - 1].x - p[1].x);
  p[n] = p[0];
  for (int i = 1; i < n; ++i) s += p[i].y * (p[i - 1].x - p[i + 1].x);
  return fabs(s * 0.5);
}
double CPIA(Point a[], Point b[], int na, int nb) {
  Point p[20], tmp[20];
  int tn, sflag, eflag;
  a[na] = a[0], b[nb] = b[0];
  memcpy(p, b, sizeof(Point) * (nb + 1));
  for (int i = 0; i < na && nb > 2; i++) {
    sflag = dcmp(cross(a[i + 1], p[0], a[i]));
    for (int j = tn = 0; j < nb; j++, sflag = eflag) {
      if (sflag >= 0) tmp[tn++] = p[j];
      eflag = dcmp(cross(a[i + 1], p[j + 1], a[i]));
      if ((sflag ^ eflag) == -2)
        tmp[tn++] = intersection(a[i], a[i + 1], p[j], p[j + 1]);
    }
    memcpy(p, tmp, sizeof(Point) * tn);
    nb = tn, p[nb] = p[0];
  }
  if (nb < 3) return 0.0;
  return PolygonArea(p, nb);
}
double SPIA(Point a[], Point b[], int na, int nb) {
  int i, j;
  Point t1[4], t2[4];
  double res = 0, num1, num2;
  a[na] = t1[0] = a[0], b[nb] = t2[0] = b[0];
  for (i = 2; i < na; i++) {
    t1[1] = a[i - 1], t1[2] = a[i];
    num1 = dcmp(cross(t1[1], t1[2], t1[0]));
    if (num1 < 0) swap(t1[1], t1[2]);
    for (j = 2; j < nb; j++) {
      t2[1] = b[j - 1], t2[2] = b[j];
      num2 = dcmp(cross(t2[1], t2[2], t2[0]));
      if (num2 < 0) swap(t2[1], t2[2]);
      res += CPIA(t1, t2, 3, 3) * num1 * num2;
    }
  }
  return res;
}
Point p1[maxn], p2[maxn];
Point rout(Point p, int d) {
  double x = p.x, y = p.y;
  double cosA = cos(d * pi / 180), sinA = sin(d * pi / 180);
  return {x * cosA - y * sinA, x * sinA + y * cosA};
}
int n1, n2;
int main() {
  int x, y, d;
  scanf("%d %d %d", &x, &y, &d);
  n1 = 4;
  p1[0].x = -x / 2.0, p1[0].y = -y / 2.0;
  p1[1].x = x / 2.0, p1[1].y = -y / 2.0;
  p1[2].x = x / 2.0, p1[2].y = y / 2.0;
  p1[3].x = -x / 2.0, p1[3].y = y / 2.0;
  n2 = 4;
  for (int i = 0; i < 4; i++) p2[i] = rout(p1[i], d);
  printf("%.10lf", SPIA(p1, p2, n1, n2));
  return 0;
}
