Question

Design a class named Triangle that extends GeometricObject class.
The class contains:
Three double data fields named side1, side2, and side3 with default values 1.0 to denote three sides of the triangle.
A no-arg constructor that creates a default triangle with color = "blue", filled = true.
A constructor that creates a triangle with the specified side1, side2, side3 and color = "blue", filled = true.
The accessor functions for all three data fields, named getSide1(), getSide2(), getSide3().
A function named getArea() that returns the area of this triangle.
A function named getPerimeter() that returns the perimeter of the triangle.
class GeometricObject
{
public:
GeometricObject(string color, bool filled)
{
    this->color = color;
    this->filled = filled;
}

string getColor() const
{ return color; }
void setColor(string color)
{ this->color = color; }
bool isFilled() const
{ return filled; }
void setFilled(bool filled)
{ this->filled = filled;}
string toString() const
{
    return "Geometric object color " + color +
    " filled " + ((filled) ? "true" : "false");
}
private:
string color;
bool filled;
};

//main.cpp

#include <iostream>
#include <string>
#include "source.h"
using namespace std;
int main()
{
Triangle shape1;
cout << shape1.getSide1() << endl;
cout << shape1.getSide2() << endl;
cout << shape1.getSide3() << endl;
cout << shape1.getArea() << endl;
cout << shape1.getPerimeter() << endl;
cout << shape1.getColor() << endl;
cout << shape1.isFilled() << endl;

Triangle shape(1, 1.5, 1);
cout << shape.getColor() << endl;
cout << shape.isFilled() << endl;

shape.setColor("yellow");
shape.setFilled(true);

cout << shape.getSide1() << endl;
cout << shape.getSide2() << endl;
cout << shape.getSide3() << endl;
cout << shape.getArea() << endl;
cout << shape.getPerimeter() << endl;
cout << shape.getColor() << endl;
cout << shape.isFilled() << endl;

return 0;
}

//source.h

???

Answer 1

I modified the code and here is the solution to the problem.

<source.h> header has the following code:

#include <iostream>
#include<math.h>
using namespace std;
// just one no-arg constructor is added to GeometricObject class. It is explained below why.
// remaining is kept the same
class GeometricObject
{
   public:
       GeometricObject()
       {
           color = "blue";
           filled = true;
       }
       GeometricObject(string color, bool filled)
       {
       this->color = color;
       this->filled = filled;
       }
       string getColor() const
       {
           return color;
       }
       void setColor(string color)
       {
           this->color = color;
       }
       bool isFilled() const
       {
           return filled;
       }
       void setFilled(bool filled)
       {
           this->filled = filled;
       }
       string toString() const
       {
       return "Geometric object color " + color +
       " filled " + ((filled) ? "true" : "false");
       }
       private:
       string color;
       bool filled;
};

//create a Triangle class which extends the GeometricObject class and performs it's own functions
class Triangle : public GeometricObject
{
   //declare the sides as private
   private:
       double side1,side2,side3;
   //remaining all functions are public
   public:
       // a no-arg constructor and initializing the sides to 1 each.
       /*This constructor will look for it's own parent no-arg contructor
       When found will execute the same.
       Hence, it's important to have a no-arg constructor in GeometricObject class*/
       Triangle()
       {
           side1 = 1;
           side2 = 1;
           side3 = 1;
       }
       // with given values change the parameter values using this constructor
       Triangle(double s1, double s2, double s3)
       {
           side1 = s1;
           side2 = s2;
           side3 = s3;
           setColor("blue");
           setFilled(true);
       }
       // return the sides using these getter functions
       double getSide1() const
       {
           return side1;
       }
       double getSide2() const
       {
           return side2;
       }
       double getSide3() const
       {
           return side3;
       }  
       //use this function to return area
       double getArea()
       {
           double s = getPerimeter()/2;
           double ar = sqrt(s*(s-side1)*(s-side2)*(s-side3));
           return ar;
       }
       //use this function to get the perimeter
       double getPerimeter()
       {
           return (side1+side2+side3);
       }
};
main.cpp has the following code:

#include"source.h"int main()
{
   Triangle shape1;
   cout << "The side1 of shape1 object is:\t"<<shape1.getSide1() << endl;
   cout << "The side2 of shape1 object is:\t"<<shape1.getSide2() << endl;
   cout << "The side1 of shape3 object is:\t"<<shape1.getSide3() << endl;
   cout << "The area of shape1 object is:\t"<<shape1.getArea() << endl;
   cout << "The perimeter of shape1 object is:\t"<<shape1.getPerimeter() << endl;
   cout << "The color of shape1 object is:\t"<<shape1.getColor() << endl;
   cout << "Is the triangle filled for shape1 object?\t";
   if(shape1.isFilled()==1)
   cout<<"Yes"<<endl;
   else
   cout<<"No"<<endl;
  
// *****New object creation*****
  
   cout << "\n\n****New Object***\n\n" << endl;
   Triangle shape(1, 1.5, 1);
   cout << "The color of shape object is:\t"<< shape.getColor() << endl;
   cout << "Is the triangle filled for shape object?\t";
   if(shape.isFilled()==1)
   cout<<"Yes"<<endl;
   else
   cout<<"No"<<endl;
   cout<<"Setting color for shape object to yellow...." << endl;
   shape.setColor("yellow");
   cout<<"Setting filled for shape object to true...." << endl;
   shape.setFilled(true);
  
   cout << "The side1 of shape object is:\t"<< shape.getSide1() << endl;
   cout << "The side2 of shape object is:\t"<< shape.getSide2() << endl;
   cout << "The side3 of shape object is:\t"<< shape.getSide3() << endl;
   cout << "The area of shape object is:\t"<< shape.getArea() << endl;
   cout << "The perimeter of shape object is:\t"<< shape.getPerimeter() << endl;
   cout << "The color of shape object is:\t"<< shape.getColor() << endl;
   cout << "Is the triangle filled for shape object?\t";
   if(shape.isFilled()==1)
   cout<<"Yes"<<endl;
   else
   cout<<"No"<<endl;
   return 0;
}

Output: