입체도형 구하는 프로그래밍입니다. 부탁드립니다..

#include<iostream>
using namespace std;
class Rectangle
{
protected:
	float lengtha,lengthb, height;
public:
	Rectangle() : lengtha(0.0),lengthb(0.0), height(0.0)
	{
		cout << "가로를 입력하시오: ";
		cin >> lengtha;
		cout << "세로를 입력하시오";
		cin >> lengthb;
		cout << "높이를 입력하시오";
		cin >> height;
	}
};
class Recvolume : public Rectangle
{
public:
		float volume()
		{
			return lengtha*lengthb*height;
		}
};
class RecArea : public Rectangle
{
public:
	float area()
	{
		return (lengtha*height) * 2 + (lengtha*lengthb) * 2 + (lengthb*height) * 2;
	}
};
class Square
{
protected:
	float lengtha, lengthb, height;
public:
	Square() : lengtha(0.0), lengthb(0.0), height(0.0)
	{
		cout << "가로를 입력하시오: ";
		cin >> lengtha;
		cout << "세로를 입력하시오";
		cin >> lengthb;
		cout << "높이를 입력하시오";
		cin >> height;
	}
};
class Squavolume : public Square
{
public:
	float volume()
	{
		return lengtha*lengthb*height;
	}
};
class SquaArea : public Square
{
public:
	float area()
	{
		return (lengtha*height) * 2 + (lengtha*lengthb) * 2 + (lengthb*height) * 2;
	}
};
class Pitch
{
protected:
	float r  ;
public:
	Pitch() : r(0.0)
	{
		cout << "반지름을 입력하시오(π=3.14로 계산) ";
		cin >> r;
	}
};
class Pitvolume : public Pitch
 
{
public:
	double volume()
	{
		return 4 / 3 * 3.14*r*r;
	}
};
 
class PitArea : public Pitch
{
public:
	double area()
	{
		return 4 * 3.14 * r * r;
	}
};
class Cone
{
protected:
	float r ,height, l;
public:
	Cone(): r(0.0), height(0.0), l(0.0)
	{
		cout << "반지름을 입력하시오(π=3.14로 계산) ";
		cin >> r;
		cout << "높이를 입력하시오: ";
		cin >> height;
		cout << "호의 길이를 구하시오: ";
		cin >> l;
	}
};
class ConeVolume : public Cone
{
public:
	double volume()
	{
		return 1 / 3 * 3.14*r*r*height;
	}
};
class ConeArea : public Cone
{
public:
	double area()
	{
		return 3.14*r*r + 3.14*r*l;
	}
};
 
int main()
{
	char menu;
 
 
	while (true)
	{
		//메뉴출력
		cout << "1.직육면체 부피, 넓이 구하기\n";
		cout << "2.정육면체 부피, 넓이 구하기\n";
		cout << "3.구   부피, 넓이 구하기\n";
		cout << "4.원뿔 부피, 넓이 구하기\n";
		cout << "5.종료\n";
		cout << "메뉴 선택: ";
		cin  >> menu;
 
		if (menu == '5')
			break;
 
		switch (menu)
		{
 
		case '1':{
			Rectangle b;
			cout << "Enter data for first rectangle to find area.\n";
			Recvolume a;
			cout << "직육면체의 부피는: "<<  << "입니다";
 
			cout << "직육면체의 넓이는: ";
		}
				 break;
		case '2':{
 
			cout << "정육면체의 부피는: ";
 
			cout << "정육면체의 넓이는: ";
		}
				 break;
		case'3':{
 
			cout << "구의 부피는: ";
 
			cout << "구의 넓이는: ";
		}
				break;
		case '4':{
 
			cout << "원뿔의 부피는: ";
 
			cout << "원뿔의 넓이는: ";
		}
				 break;
		}
	}
 
	return 0;
}