Coordinate conversion in c++ - c++

Question

I am trying to convert different coordinate systems. From polar to rectangular and vice versa. My pol_to_rect()function is not working properly. It is giving very small values(~10^(-44)) after converting and also before converting. There might be some problem while using the sin() and cos() functions. The rect_to_pol() is working fine for positive values.
Edit - When I changed atan() to atan2() how can I incorporate other values of x and y.
#include <iostream>
#include <cmath>
using namespace std;
#define PI 3.1415926
class Polar; // Forward declaration
class Rectangular {
private:
float x, y;
public:
Rectangular() {} // default constructor
Rectangular(float mv_x, float mv_y) {
x = mv_x;
y = mv_y;
}
void showData() const;
Polar rect_to_pol();
float& get_x() {
return x;
}
float& get_y() {
return y;
}
};
void Rectangular::showData() const {
cout << "--Rectangular--" << endl;
cout << "x: " << x << "\t" <<"y: " << y << endl;
}
class Polar {
private:
float r;
float theta;
public:
Polar() {} // default constructor
Polar(float mv_r, float mv_theta) {
r = mv_r;
theta = mv_theta;
}
void showData();
Rectangular pol_to_rect();
float& get_r(){
return r;
}
float& get_theta() {
return theta;
}
};
void Polar::showData() {
cout << "--Polar--" << endl;
cout << "r:" << r << "\t" << "Theta(Radians):" << theta << endl;
}
Rectangular Polar::pol_to_rect() {
Rectangular temp;
temp.get_x() = r * cos(theta*(PI/180.0)); // in degrees
temp.get_y() = r * sin(theta*(PI/180.0));
return temp;
}
Polar Rectangular::rect_to_pol() {
Polar temp;
temp.get_r() = sqrt(pow(x, 2) + pow(y, 2));
temp.get_theta() = atan2(y, x);
return temp;
}
int main()
{
Rectangular r1(-1, -1), r2;
Polar p1(12.0, 30.0), p2;
r1.showData();
p2 = r1.rect_to_pol();
cout << "After Conversion (RECT TO POLAR)->" << endl;
p2.showData();
p1.showData();
r2 = p1.pol_to_rect();
cout << "After Conversion (POLAR TO RECT)" << endl;
r2.showData();
return 0;
}