I am trying to define centroid in the following code as centroid is part of the private data for this class. But when I output the data it reads 0, 0 instead of the real values. Vec is a 3 dimension class that i have created. I'm not sure what could be wrong.. Help!!

Header file:

```
//////////////////////////////////////////////////
/// \class triangle
/// \brief triangle class
/// ///////////////////////////////////////////////
/// \file triangle.h
/// \brief provide a set fo functions to facilitate triangle manipulations
//////////////////////////////////////////////////
#include <math.h>
#include <iostream>
#include <fstream>
#include "list.h"
#include "vec.h"
#include "circle.h"
using namespace std;
#ifndef TRIANGLE_H
#define TRIANGLE_H
class triangle : public ListElement
{
public:
friend ostream & operator << (ostream& out, const triangle& inTriangle);
virtual double ElementValue(void);
/// \brief Non-default Constructor
triangle(const unsigned int id_in, const Vec iIn, const Vec jIn, const Vec kIn,
const Vec triNodeIDin);
/// \brief Destructor
~triangle(){};
/// \brief Calculate the centroid of a triangle
Vec get_centroid(void){return centroid;}
/// \brief Calculate the area of a triangle
double get_area(void){return area;}
/// \brief Prints out the triangle area
virtual void print(void) {cout << "Tri area: " << ElementValue() << endl;}
/// \brief Writes out the triangle data
virtual void out(ofstream& myfile);
private:
unsigned int id;
Vec i; /// <First node of triangle
Vec j; /// <Second node of triangle
Vec k; /// <Third node of triangle
Circle theCircle;
Vec centroid;
double area;
Vec triNode;
};
#endif // TRIANGLE_H
```

The source file constructor:

```
triangle::triangle(unsigned int id_in, Vec iIn, Vec jIn, Vec kIn, Vec triNodeIDin):
id(id_in), i(iIn), j(jIn), k(kIn),theCircle(iIn, jIn, kIn), triNode(triNodeIDin){
/// Method:
/// -Takes in nothing
/// -Calculate the area of a triangle using vectors
/// \param void
/// \return area of the triangle
Vec vecA(i[0], i[1], 0);
Vec vecB(j[0], j[1], 0);
Vec vecC(k[0], k[1], 0);
Vec vecAB = vecA-vecB;
Vec vecAC = vecA-vecC;
area = ((vecAB*vecAC).norm())*0.5;
/// Method:
/// -Takes in nothing
/// -Compute the x, y coordinates of the centroid
/// \param void
/// \return centroid of a triangle
double cX = (i[0]+j[0]+k[0])/3;
double cY = (i[1]+j[1]+k[1])/3;
double cZ = 0;
centroid(cX, cY, cZ);
}
```