원을 만드는 것

#include<iostream>

class Circle{

private:

int rad;

public:

Circle(int r){ rad = r; }

double getarea(){ return 3.14 * rad * rad; }

};

int main(void){

Circle a(6),b(7),c(8);

std::cout << a.getarea() << '\n';

std::cout << b.getarea() << '\n';

std::cout << c.getarea() << '\n';

return 0;

}