//A menu driven program to find area of shapes
#include <iostream>
using namespace std;
//function prototypes
void circle(void);           //finds area of circle
void square(void);           //finds area of square
void rectangle(void);        //finds area of rectangle
void menu(void);             //displays choices
void doChoice(char choice);  //calls function selected
void wait(void);             //waits for user to press a key

void main(void)  //display menu and call function selected
{ char choice;
  do
  { menu();            //display choices
    cin>>choice;
    doChoice(choice);  //calls function selected
  } while ((choice != 'Q') && (choice !='q'));  
} //main

void doChoice(char choice) //calls function selected
{ switch (choice)
  {  case 'C': case 'c': circle(); break;
     case 'R': case 'r': rectangle(); break;
     case 'S': case 's': square(); break;
  } //choice
  wait();  //lets user look at result before menu is displayed
} //doChoice

void menu(void) //display the choices
{ cout<<"This will find the area of a shape\n\n";
  cout<<"Enter the letter of your choice: \n";
  cout<<"C: Circle\n";
  cout<<"R: Rectangle\n";
  cout<<"S: Square\n\n";
  cout<<"Q: Quit\n";
  cout<<"Please enter your choice:";
} //menu

void circle(void) //find area of circle from radius
{ double radius, area;
  cout<<"Enter the radius of the circle:";
  cin>>radius;
  area = radius*radius*3.14158;
  cout<<"The area is "<<area<<"\n";
} //circle

void rectangle(void) //find area of rectangle from length and width
{ double length, width, area;
  cout<<"Enter the width of the rectangle:";
  cin>>width;
  cout<<"Enter the length of the rectangle:";
  cin>>length;
  area = width * length;
  cout<<"The area is "<<area<<"\n";
} //square 

void square(void) //find area of square from side
{ double side, area;
  cout<<"Enter the side of the square:";
  cin>>side;
  area = side * side;
  cout<<"The area is "<<area<<"\n";
} //square

void wait(void)  //waits for user to press ENTER before continuing
{ char ch;
  cout<<"Press ENTER to continue";
  cin.ignore(100,'\n'); //clear anything in the input stream
  cin.get(ch);         //wait for a character to be entered
  cout<<"\n\n";        //print 2 blank lines
} //wait