Question

Create a menu-driven program (using the switch) that finds and displays areas of 3 different objects.

The menu should have the following 4 choices:

1 -- rectangle

2 -- circle

3 -- triangle

4 -- quit

• If the user selects choice 1, the program should find the area of a rectangle.
  • rectangle area = length * width
• If the user selects choice 2, the program should find the area of a circle.
  • circle area = PI * radius * radius (PI = 3.14159)
• If the user selects choice 3, the program should find the area of a triangle.
  • triangle area = base * height * 0.5
• If the user selects choice 4, the program should quit without doing anything.

If the user selects anything else (i.e., an invalid choice) an appropriate error message should be printed.

HINTS:

// 1. DEFINE THE NAMED CONSTANT PI AND SET ITS VALUE TO 3.14159
// 2. DECLARE ALL NEEDED VARIABLES and GIVE EACH ONE A DESCRIPTIVE NAME
// AND AN APPROPRIATE DATA TYPE.
// 3. USE AN IF/ELSE IF STATEMENT TO OBTAIN ANY NEEDED INPUT INFORMATION
// AND COMPUTE AND DISPLAY THE AREA FOR EACH VALID MENU CHOICE.
// 4. IF AN INVALID MENU CHOICE WAS ENTERED, AN ERROR MESSAGE SHOULD
// BE DISPLAYED.

Sample Run

Program to calculate areas of objects

   1 -- rectangle

        2 -- circle

        3 -- triangle

        4 -- quit

2

Radius of the circle: 3.0

Area = 28.2743

Answer 1

Program:

#include <iostream>

using namespace std;

int main()
{
int ch;
cout<<"1).rectangle"<<endl;
cout<<"2).circle"<<endl;
cout<<"3).triangle"<<endl;
cout<<"4).quit"<<endl;
cout<<"Enter your choice: ";
cin>>ch;
  
switch(ch)
{
case 1:
float l,w;
cout<<"Length of rectangle: ";
cin>>l;
cout<<"Width of rectangle: ";
cin>>w;
  
cout<<endl<<"Area: "<<(l*w);
break;
  
case 2:
float r;
cout<<"Radius of the circle: ";
cin>>r;
  
cout<<endl<<"Area: "<<(3.14159 * r * r);
  
break;
  
case 3:
float b,h;
cout<<"Base of circle: ";
cin>>b;
cout<<"Height of circle: ";
cin>>h;
  
cout<<endl<<"Area: "<<(b* h* 0.5);
break;
  
case 4:
cout<<"You choose to quit, bye!";
break;
  
default:
cout<<"Invalid choice";
break;
}
return 0;
}

Output: