Answer to Question #329951 in C++ for mak

Question

Create a class named ‘CalculateArea’ to calculate the area of three different diagrams i.e. Rectangle, Triangle and a Square using function overloading.

First prompt the user to select the diagram for which he wants the area:

Press 1 for Rectangle

Press 2 for Triangle

Press 3 for Square

After the selected option, call the respective function of the selected diagram and print the area.

Area of rectangle: length*width;

Area of triangle: ½(base*height);

Area of square: (length)²

Answer 1

#include <iostream>


using namespace std;


class CalculateArea
{
public:
	virtual float Calculate() = 0;
	virtual void Assign() = 0;
};


class Rectangl:public CalculateArea
{
	float length;
	float width;
public:
	Rectangl(float _length=0, float _width=0)
	:length(_length), width(_width){}
	void Assign()
	{
		cout << "Please, enter a length: ";
		cin >> length;
		cout << "Please, enter a width: ";
		cin >> width;
	}
	float Calculate()
	{
		return length*width;
	}
};


class Triangle :public CalculateArea
{
	float base;
	float height;
public:
	Triangle(float _base = 0, float _height = 0)
		:base(_base), height(_height) {}
	void Assign()
	{
		cout << "Please, enter a base: ";
		cin >> base;
		cout << "Please, enter a height: ";
		cin >> height;
	}
	float Calculate()
	{
		return base*height*0.5;
	}
};


class Square :public CalculateArea
{
	float length;
public:
	Square(float _length = 0):length(_length){}
	void Assign()
	{
		cout << "Please, enter a length: ";
		cin >> length;
	}
	float Calculate()
	{
		return length*length;
	}
};




void Menu()
{
	cout << "\nSelect from the following:";
	cout << "\nPress 1 for Rectangle"
		<< "\nPress 2 for Triangle"
		<< "\nPress 3 for Square"
		<< "\nPress 0 for Exit";
	cout << "\nMake a select: ";
}


int main()
{
	CalculateArea* p;
	char ch;
	do
	{
		Menu();
		cin >> ch;
		switch (ch)
		{
			case '1':
			{
				Rectangl r;
				p = &r;
				p->Assign();
				cout << "Resulting area is " << p->Calculate();
				break;
			}
			case '2':
			{
				Triangle t;
				p = &t;
				p->Assign();
				cout << "Resulting area is " << p->Calculate();
				break;
			}
			case '3':
			{
				Square s;
				p = &s;
				p->Assign();
				cout << "Resulting area is " << p->Calculate();
				break;
			}
		}
	} while (ch != '0');
}