Классы "Фигура", "Прямоугольник", "Круг"

#define _USE_MATH_DEFINES
#include <iostream>
#include <cmath>
using namespace std;
 
class Figure
{
public:
virtual void Show()=0;
virtual double GetArea()=0;
virtual double GetPerimeter()=0;
};
class Rectangle : public Figure
{ 
private:
double a;
double b;
public:
Rectangle():a(0),b(0)
{}
Rectangle(double a,double b):a(a),b(b)
{}
double GetPerimeter()
{
return 2*(a+b);
}
double GetArea()
{
return a*b;
}
void Show()
{
cout<<"Ñòîðîíû ïðÿìîóãîëüíèêà: "<<a<<" "<<b<<endl;
cout<<"Ïåðèìåòð ïðÿìîóãîëüíèêà: "<<GetPerimeter()<<endl;
cout<<"Ïëîùàäü ïðÿìîóãîëüíèêà: "<<GetArea()<<endl;
cout<<'\n'<<endl;
}
};
class Circle : public Figure
{
private:
double x;
double y;
double radius;
public:
Circle():x(0),y(0),radius(0)
{}
Circle(double x,double y,double radius):x(x),y(y),radius(radius)
{}
double GetPerimeter()
{
return 2*M_PI*radius;
}
double GetArea()
{
return M_PI*radius*radius;
}
void Show()
{
cout<<"Öåíòð îêðóæíîñòè: "<<x<<" "<<y<<endl;
cout<<"Ðàäèóñ îêðóæíîñòè: "<<radius<<endl;
cout<<"Äëèíà Îêðóæíîñòè : "<<GetPerimeter()<<endl;
cout<<"Ïëîùàäü Îêðóæíîñòè: "<<GetArea()<<endl;
cout<<'\n'<<endl;
}
};
 
class Triangle : public Figure
{
private:
double a;
double b;
double c;
public:
Triangle():a(0),b(0),c(0)
{}
Triangle(double a,double b,double c):a(a),b(b),c(c)
{}
double GetPerimeter()
{
return a+b+c;
}
double GetArea()
{
double p=(a+b+c)/2;
return sqrt(p*(p-a)*(p-b)*(p-c));
}
void Show()
{
cout<<"Ñòîðîíû òðåóãîëüíèêà: "<<a<<" "<<b<<" "<<c<<endl;
cout<<"Ïåðèìåòð òðåóãîëüíèêà: "<<GetPerimeter()<<endl;
cout<<"Ïëîùàäü òðåóãîëüíèêà: "<<GetArea()<<endl;
cout<<'\n'<<endl;
}
};
 
int main()
{ setlocale(LC_ALL,"Russian");
Figure *objects[6];
objects[0]= new Triangle(3,8,7);
objects[1]= new Triangle(3,4,5);
objects[2]= new Rectangle(8,2);
objects[3]= new Rectangle(10,5);
objects[4]= new Circle(3,4,8);
objects[5]= new Circle(7,3,2);
for(int i=0;i<6;i++)
{
objects[i]->Show();
}
system("pause");
return 0;
}

#include <cstdlib>