// 简单多边形与圆面积交
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
using namespace std;
const double eps = 1e-8;
const double pi = acos(-1.0);
const int maxn = 103;
struct Point {
    double x, y;
    Point(){}
    Point (double tx,double ty)
    {
        this->x = tx;
        this->y = ty;
    }
    Point operator - (const Point &t) const {
        Point res;
        res.x = x - t.x;
        res.y = y - t.y;
        return res;
    }
}p[maxn];
double multi(Point &o, Point &a, Point &b) {                            // 点积
    return (a.x-o.x)*(b.x-o.x) + (a.y-o.y)*(b.y-o.y);
}
double cross(Point &o, Point &a, Point &b) {                            // 叉积
    return (a.x-o.x)*(b.y-o.y) - (b.x-o.x)*(a.y-o.y);
}
double cp(Point &a, Point &b) {
    return a.x*b.y - b.x*a.y;
}
double angle(Point &a, Point &b) {                                              // 两向量夹角
    double ans = fabs((atan2(a.y, a.x) - atan2(b.y, b.x)));
    return ans > pi+eps ? 2*pi-ans : ans;
}
void cir_line(Point ct, double r, Point l1, Point l2, Point& p1, Point& p2) {   // 直线与圆
    double a1, a2, b1, b2, A, B, C, t1, t2;
    a1 = l2.x - l1.x; a2 = l2.y - l1.y;
    b1 = l1.x - ct.x; b2 = l1.y - ct.y;
    A = a1*a1 + a2*a2;
    B = (a1*b1 + a2*b2)*2;
    C = b1*b1 + b2*b2 - r*r;
    t1 = (-B - sqrt(B*B - 4.0*A*C))/2.0/A;
    t2 = (-B + sqrt(B*B - 4.0*A*C))/2.0/A;
    p1.x = l1.x + a1*t1; p1.y = l1.y + a2*t1;
    p2.x = l1.x + a1*t2; p2.y = l1.y + a2*t2;
}
double cir_polygon(Point ct, double R, Point *p, int n) {                   // 圆与简单多边形
    Point o, a, b, t1, t2;
    double sum=0, res, d1, d2, d3, sign;
    o.x = o.y = 0;
    p[n] = p[0];
    for (int i=0; i < n; i++) {
        a = p[i]-ct;
        b = p[i+1]-ct;
        sign = cp(a,b) > 0 ? 1 : -1;
        d1 = a.x*a.x + a.y*a.y;
        d2 = b.x*b.x + b.y*b.y;
        d3 = sqrt((a.x-b.x)*(a.x-b.x) + (a.y-b.y)*(a.y-b.y));
        if (d1 < R*R+eps && d2 < R*R+eps) { //两个点都在圆内
            res = fabs(cp(a, b));
        }
        else if (d1 < R*R-eps || d2 < R*R-eps) { //一个点在圆内
            cir_line(o, R, a, b, t1, t2);
            if ((a.x-t2.x)*(b.x-t2.x) < eps && (a.y-t2.y)*(b.y-t2.y) < eps) {
                t1 = t2;
            }
            if (d1 < d2)
                res = fabs(cp(a, t1)) + R*R*angle(b, t1);
            else
                res = fabs(cp(b, t1)) + R*R*angle(a, t1);
        }
        else if (fabs(cp(a, b))/d3 > R-eps) { // 两个点都在园外，且线段与圆之多只有一个交点
            res = R*R*angle(a, b);
        }
        else {  // 线段与圆有两个交点
            cir_line(o, R, a, b, t1, t2);
            if (multi(t1, a, b) > eps || multi(t2, a, b) > eps) {
                res = R*R*angle(a, b);
            }
            else {
                res = fabs(cp(t1, t2));
                if (cross(t1, t2, a) < eps)
                    res += R*R*(angle(a, t1) + angle(b, t2));
                else
                    res += R*R*(angle(a, t2) + angle(b, t1));
            }
        }
        sum += res * sign;
    }
    return fabs(sum)/2.0;
}
int main()
{
    int t,ca=1;
    scanf("%d",&t);
    while(t--)
    {
        Point cen;
        double R;
        scanf("%lf%lf%lf",&cen.x,&cen.y,&R);
        Point p[4]; double a,b,c,d;
        scanf("%lf%lf%lf%lf",&a,&b,&c,&d);
        p[0] = Point(a,b);
        p[1] = Point(c,b);
        p[2] = Point(c,d);
        p[3] = Point(a,d);
        printf("Case %d: %lf\n",ca++,cir_polygon(cen,R,p,4));
    }
    return 0;
}