# No designer - circumference

• Parameter circumference: centre coordinates, radius. Methods: Procedure for initialization of fields, procedure for displaying the object &apos; s field values and function for determining whether a point is located at coordinates x,y inside the circumference. Created as he could, when compiling makes error: ‘x’ was not declared in this scope

``````
#include <iostream>
#include <cmath>
using namespace std;
class Circle
{
private:
double x;
double y;
double r;
public:
Circle();
Circle(double x=2, double y=2, double r=5);
};
int Main(){
if (xx+yy<=r*r)
{
cout << "Точка принадлежит окружности." << endl;
}
else
{
cout << "Точка не принадлежит окружности." << endl;
}
return 0;
}
``````

• Your function. `int Main()` is not a class method (based outside) and therefore knows nothing about variables `x, y, r`but you use them in this function.

``````class Circle
{
private:
double x;
double y;
double r;
public:
Circle();
Circle(const double x0=2, const double y0=2, const double r0=5);
int Main();

};
int Circle::Main(){
if (xx+yy<=r*r)
{
cout << "Точка принадлежит окружности." << endl;
}
else
{
cout << "Точка не принадлежит окружности." << endl;
}
return 0;
}
``````

I really suspect it. `Main()`which `main()` usually :

P. S.

``````class Circle
{
private:
double x;
double y;
double r;
public:
Circle();
Circle(const double x0=2, const double y0=2, const double r0=5);
void show();

};
Circle::Circle()
: x(0), y(0), r(0)
{}
Circle::Circle(const double x0, const double y0, const double r0)
: x(x0), y(y0), r(r0)
{}
int Circle::show(){
if (xx+yy<=r*r)
{
cout << "Точка принадлежит окружности." << endl;
}
else
{
cout << "Точка не принадлежит окружности." << endl;
}
return 0;
}
``````

and use in the main code, for example:

``````Circle obj(10, 20, 5);
obj.show();
``````

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