Nesting Inheritance LNK2001 and LNK1120 error - c++

Question

My code isn't working. I'm trying simple inheritance Shape as base class and two classes under Shape "Two Dimension" and "Three Dimension" and shapes under that classes. Here's my code but when I try to define a new class as Triangle it gives me error LNK2001 LNK1120. It looks complicated but I must get area, volume and perimeter for every each object.
My full error:
Severity Code Description Project File Line Suppression State
Error LNK2001 unresolved external symbol "public: virtual double __thiscall TwoDimensionShape::Area(void)" (?Area#TwoDimensionShape##UAENXZ) Shape c:\Users\aleyn\documents\visual studio 2015\Projects\Shape\Shape\Source.obj 1
That's .h
#pragma once
#define M_PI 3.14159265358979323846
class Shape
{
private:
double width, height, depth;
public:
Shape(double w, double h, double d);
virtual void Display() = 0;
virtual double Area() = 0;
virtual double Perimeter() = 0;
virtual double Volume() = 0;
};
class TwoDimensionShape: public Shape
{
public:
TwoDimensionShape(double w, double h, double d = 0) :
Shape(w, h, d)
{
}
double Area();
double Perimeter();
double Volume();
void Display();
};
class ThreeDimensionShape: public Shape
{
private:
double width, height, depth;
public:
ThreeDimensionShape(double w, double h, double d) :
Shape(w, h, d)
{
depth = d;
}
double Area();
double Volume();
double Perimeter();
void Display();
};
class Triangle: public TwoDimensionShape
{
private:
double side1, side2, base;
public:
Triangle(double w, double h, double d = 0) :
TwoDimensionShape(w, h, d)
{
}
double Area()
{
return Area() / 2;
}
void setTriangleSides(double s1, double s2, double b);
double Perimeter()
{
return side1, side2, base;
}
double Volume()
{
return 0;
}
};
class Square: public TwoDimensionShape
{
public:
Square(double w, double h, double d = 0) :
TwoDimensionShape(w, h, d)
{
}
double Volume()
{
return 0;
}
};
class Rectangle: public TwoDimensionShape
{
public:
Rectangle(double w, double h, double d = 0) :
TwoDimensionShape(w, h, d)
{
}
double Volume()
{
return 0;
}
};
class Circle: public TwoDimensionShape
{
private:
double radius;
public:
Circle(double r, double a = 0, double d = 0) :
TwoDimensionShape(r, a, d)
{
radius = r;
}
double Area()
{
return M_PI * (radius) * (radius);
}
double Perimeter()
{
return 2 * M_PI * radius;
}
double Volume()
{
return 0;
}
};
class Sphere: public ThreeDimensionShape
{
private:
double radius;
public:
Sphere(double r, double a = 0, double b = 0) :
ThreeDimensionShape(r, a, b)
{
radius = r;
}
double Volume()
{
return (4 / 3 * M_PI * (radius * radius * radius));
}
double Area()
{
return 4 * M_PI * radius * radius;
}
double Perimeter()
{
return 0;
}
};
class Cylinder: public ThreeDimensionShape
{
private:
double radius, height;
public:
Cylinder(double r, double h, double a = 0) :
ThreeDimensionShape(r, h, a)
{
}
double Volume()
{
return M_PI * radius * radius * height;
}
double Area()
{
return (2 * M_PI * radius * height) + 2 * M_PI * radius * radius;
}
double Perimeter()
{
return 0;
}
};
class Cone: public ThreeDimensionShape
{
private:
double radius, height, side;
public:
Cone(double r, double h, double s) :
ThreeDimensionShape(r, h, s)
{
}
double Volume()
{
return 1 / 3 * M_PI * radius * radius * height;
}
double Area()
{
return (M_PI * radius * side) + M_PI * radius * radius;
}
double Perimeter()
{
return 0;
}
};
class RectPrism: public ThreeDimensionShape
{
public:
RectPrism(double w, double h, double d) :
ThreeDimensionShape(w, h, d)
{
}
double Area();
double Volume();
double Perimeter();
};
my .cpp
#include "Shape.h"
#include <iostream>
using namespace std;
Shape::Shape(double w, double h, double d)
{
width = w;
height = h;
depth = d;
}
double Shape::Area()
{
return width * height;
}
double Shape::Perimeter()
{
return (width + height) * 2;
}
double Shape::Volume()
{
return width * height * depth;
}
double ThreeDimensionShape::Area()
{
return (2 * (height * width) + 2 * (depth * width) + 2 * (depth * height));
}
double ThreeDimensionShape::Volume()
{
return width * height * depth;
}
double ThreeDimensionShape::Perimeter()
{
return (4 * width + 4 * height + 4 * depth);
}
void Triangle::setTriangleSides(double s1, double s2, double b)
{
side1 = s1;
side2 = s2;
base = b;
}
void TwoDimensionShape::Display()
{
cout << "Perimeter: " << Perimeter() << endl;
cout << "Area: " << Area() << endl;
cout << "Volume: " << Volume() << endl;
}
main .cpp
#include <iostream>
#include "Shape.h"
using namespace std;
int main()
{
Triangle t1(8, 5, 0);
system("pause");
return 0;
}

Answer 1

the error message says it all
LNK2001 unresolved external symbol "public: virtual double __thiscall TwoDimensionShape::Area(void)"
You have not written TwoDimenionalShape::Area
In your header file you promised to write one, but you didnt