determine the shape

#include<stdio.h>
#include<math.h>

struct node{
    double x;
    double y;
};

double distace(double x1, double y1, double x2, double y2)
{
    double d;
    d=sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
    return d;
}

double slop(double x1, double y1, double x2, double y2)
{
    double m;
    if(x1==x2)
        m=10009;
    else
        m=(y2-y1)/(x2-x1);
    return m;
}

int main()
{
    int n,i;
    double ab,bc,cd,da;
    double abm,bcm,cdm,dam;
    struct node a,b,c,d;
    freopen("input.txt","r",stdin);
    scanf("%d",&n);
    for(i=1;i<=n;i++){
        scanf("%lf %lf",&a.x,&a.y);
        scanf("%lf %lf",&b.x,&b.y);
        scanf("%lf %lf",&c.x,&c.y);
        scanf("%lf %lf",&d.x,&d.y);

        printf("Case %d: ",i);

        ab = distace(a.x, a.y, b.x, b.y);
        bc = distace(b.x, b.y, c.x, c.y);
        cd = distace(d.x, d.y, c.x, c.y);
        da = distace(a.x, a.y, d.x, d.y);

        abm = slop(a.x, a.y, b.x, b.y);
        bcm = slop(b.x, b.y, c.x, c.y);
        cdm = slop(d.x, d.y, c.x, c.y);
        dam = slop(a.x, a.y, d.x, d.y);

        if(ab==cd && bc==da){
            if(ab==bc){
                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                    printf("Square\n");
                else if((bcm!=10009 && abm!=10009) && abm==-(1/bcm))
                    printf("Square\n");
                else if(abm==cdm && bcm==dam)
                    printf("Rhombus\n");
            }
            else{
                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                    printf("Rectangle\n");
                else if((bcm!=10009 && abm!=10009) && ((abm==-(1/bcm))||(bcm==-(1/abm))))
                    printf("Rectangle\n");
                else if(abm==cdm && bcm==dam)
                    printf("Parallelogram\n");
            }
        }
        else{
            if(abm==cdm || bcm==dam)
                printf("Trapezium\n");
            else{
                ab = distace(a.x, a.y, b.x, b.y);
                bc = distace(b.x, b.y, d.x, d.y);
                cd = distace(c.x, c.y, d.x, d.y);
                da = distace(a.x, a.y, c.x, c.y);

                abm = slop(a.x, a.y, b.x, b.y);
                bcm = slop(b.x, b.y, d.x, d.y);
                cdm = slop(c.x, c.y, d.x, d.y);
                dam = slop(a.x, a.y, c.x, c.y);

                if(ab==cd && bc==da){
                    if(ab==bc){
                        if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                            printf("Square\n");
                        else if((bcm!=10009 && abm!=10009) && abm==-(1/bcm))
                            printf("Square\n");
                        else if(abm==cdm && bcm==dam)
                            printf("Rhombus\n");
                    }
                    else{
                        if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                            printf("Rectangle\n");
                        else if((bcm!=10009 && abm!=10009) && ((abm==-(1/bcm))||(bcm==-(1/abm))))
                            printf("Rectangle\n");
                        else if(abm==cdm && bcm==dam)
                            printf("Parallelogram\n");
                    }
                }
                else{
                    if(abm==cdm || bcm==dam)
                        printf("Trapezium\n");
                    else{
                        ab = distace(a.x, a.y, c.x, c.y);
                        bc = distace(c.x, c.y, b.x, b.y);
                        cd = distace(d.x, d.y, b.x, b.y);
                        da = distace(a.x, a.y, d.x, d.y);

                        abm = slop(a.x, a.y, c.x, c.y);
                        bcm = slop(c.x, c.y, b.x, b.y);
                        cdm = slop(d.x, d.y, b.x, b.y);
                        dam = slop(a.x, a.y, d.x, d.y);

                        if(ab==cd && bc==da){
                            if(ab==bc){
                                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                    printf("Square\n");
                                else if((bcm!=10009 && abm!=10009) && abm==-(1/bcm))
                                    printf("Square\n");
                                else if(abm==cdm && bcm==dam)
                                    printf("Rhombus\n");
                            }
                            else{
                                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                    printf("Rectangle\n");
                                else if((bcm!=10009 && abm!=10009) && ((abm==-(1/bcm))||(bcm==-(1/abm))))
                                    printf("Rectangle\n");
                                else if(abm==cdm && bcm==dam)
                                    printf("Parallelogram\n");
                            }
                        }
                        else{
                            if(abm==cdm || bcm==dam)
                            printf("Trapezium\n");
                            else{
                                ab = distace(a.x, a.y, c.x, c.y);
                                bc = distace(c.x, c.y, d.x, d.y);
                                cd = distace(b.x, b.y, d.x, d.y);
                                da = distace(a.x, a.y, b.x, b.y);

                                abm = slop(a.x, a.y, c.x, c.y);
                                bcm = slop(c.x, c.y, d.x, d.y);
                                cdm = slop(b.x, b.y, d.x, d.y);
                                dam = slop(a.x, a.y, b.x, b.y);

                                if(ab==cd && bc==da){
                                    if(ab==bc){
                                        if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                            printf("Square\n");
                                        else if((bcm!=10009 && abm!=10009) && abm==-(1/bcm))
                                            printf("Square\n");
                                        else if(abm==cdm && bcm==dam)
                                            printf("Rhombus\n");
                                    }
                                    else{
                                        if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                            printf("Rectangle\n");
                                        else if((bcm!=10009 && abm!=10009) && ((abm==-(1/bcm))||(bcm==-(1/abm))))
                                            printf("Rectangle\n");
                                        else if(abm==cdm && bcm==dam)
                                            printf("Parallelogram\n");
                                    }
                                }
                                else{
                                    if(abm==cdm || bcm==dam)
                                        printf("Trapezium\n");
                                    else{
                                        ab = distace(a.x, a.y, d.x, d.y);
                                        bc = distace(d.x, d.y, b.x, b.y);
                                        cd = distace(c.x, c.y, b.x, b.y);
                                        da = distace(a.x, a.y, c.x, c.y);

                                        abm = slop(a.x, a.y, d.x, d.y);
                                        bcm = slop(d.x, d.y, b.x, b.y);
                                        cdm = slop(c.x, c.y, b.x, b.y);
                                        dam = slop(a.x, a.y, c.x, c.y);

                                        if(ab==cd && bc==da){
                                            if(ab==bc){
                                                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                                    printf("Square\n");
                                                else if((bcm!=10009 && abm!=10009) && abm==-(1/bcm))
                                                    printf("Square\n");
                                                else if(abm==cdm && bcm==dam)
                                                    printf("Rhombus\n");
                                            }
                                            else{
                                                if((abm==10009 && bcm==0)||(abm==0 && bcm==10009))
                                                    printf("Rectangle\n");
                                                else if((bcm!=10009 && abm!=10009) && ((abm==-(1/bcm))||(bcm==-(1/abm))))
                                                    printf("Rectangle\n");
                                                else if(abm==cdm && bcm==dam)
                                                    printf("Parallelogram\n");
                                            }
                                        }
                                        else{
                                            if(abm==cdm || bcm==dam)
                                                printf("Trapezium\n");
                                            else
                                                printf("Ordinary Quadrilateral\n");
                                        }
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
    return 0;
}