三角类雏形2

#include <iostream>
#include"math.h"
using namespace std;
class triangle
{
   public:
    triangle(double x,double y,double z);
    triangle(double x,double y);
    triangle(double x);
    triangle();
    void showmessage()
    {
        cout<<a<<' '<<b<<' '<<c<<endl;
    }
   private:
       double a,b,c;

};
triangle::triangle(double x,double y,double z)
{
    a=x;
    b=y;
    c=z;
}
triangle::triangle(double x,double y)
{
    a=x;
    b=y;
    c=1;
}
triangle::triangle(double x)
{
    a=x;
    b=1;
    c=1;
}
triangle::triangle()
{
    a=1;
    b=1;
    c=1;
}




int main()
{
    triangle tril;
    tril.showmessage();
    triangle tri2(1.5);
    tri2.showmessage();
    triangle tri3(1.5,1.5);
    tri3.showmessage();
    triangle tri4(7,8,9);
    tri4.showmessage();
    return 0;
}

运行结果：