conv r.p

#include<iostream.h>
#include<conio.h>
#include<math.h>
class polar;

class rect
{
    double x,y;
public:
    rect(double a=0,double b=0)
    {
        x=a;
        y=b;
    }

    rect(polar &k)
    {
        x=k.r*cos(k.a);
        y=k.r*sin(k.a);
    }

    void display()
    {
        cout<<"the rectangular co-ordinates:\n x = "<<x<<" and y = "<<y<<endl;
    }
};

class polar
{
    double r,a;
public:
    polar(double c=0,double b=0)
    {
        r=c;
        a=(3.14/180)*b;
    }

    polar(rect &k)
    {
        r=sqrt(k.x*k.x+k.y*k.y);
        a=atan(k.y/k.x);
    }

    polar operator+(polar &t)
    {
        polar fin;
        double x,y,z,s;
        x=r*cos(a);
        y=r*sin(a);
        z=t.r*cos(t.a);
        s=t.r*sin(t.a);
        x=x+z;
        y=y+s;
        fin.a=atan(y/x);
        fin.r=sqrt(x*x+y*y);
        return fin;
    }

    void display()
    {
        cout<<"the polar co-ordinates:\n radius is = "<<r<<" and the angle = "<<a<<endl;
    }
};



int main()
{
    polar p1,p2,p3;
    rect r1;
    double x,y;
    int a,t=1,i;
    do
    {
        cout<<"enter a choice:\n";
        cout<<"1.add two polar co-ordinates\n";
        cout<<"2.convert from polar to rectangular co-ordinates\n";
        cout<<"3.convert from rectangular to polar co-ordinates\n";
        cout<<"4.exit\n";
        cin>>a;
        switch(a)
        {
        case 1:
            cout<<"enter the values of the radius and angle of the two co-ordinates:\n";
            for(i=1;i<=2;i++)
            {
                cout<<"radius and angle in degrees of "<<i<<" No.:\n";
                cin>>x>>y;
                if(i==1)
                    p1=polar(x,y);
                else
                    p2=polar(x,y);
            }
            p3=p1+p2;
            cout<<"the result is:\n";
            p3.display();
            break;

        case 2:
            cout<<"enter the values of the radius and angle of the co-ordinates:\n";
            cout<<"radius and angle in degrees:\n";
            cin>>x>>y;
            p1=polar(x,y);
            r1=p1;
            r1.display();
            break;

        case 3:
            cout<<"enter the values of x and y:\n";
            cin>>x>>y;
            r1=rect(x,y);
            p1=r1;
            p1.display();
            break;

        case 4:
            t=0;
            break;

        default:
            cout<<"invalid\n";
            break;
        }
    }while(t!=0);
    return 0;
}