// Listing 5.1 - demonstrates the use of function prototypes
 #include <iostream>

 int FindArea(int length, int width); //function prototype (declaration)

 int main()
 {
     int lengthOfYard;
     int widthOfYard;
     int areaOfYard;

     std::cout << "\nHow wide is your yard? ";
     std::cin >> widthOfYard;
     std::cout << "\nHow long is your yard? ";
     std::cin >> lengthOfYard;

     areaOfYard= FindArea(lengthOfYard,widthOfYard);

     std::cout << "\nYour yard is ";
     std::cout << areaOfYard;
     std::cout << " square feet\n\n";
     return 0;
 }

 int FindArea(int l, int w) // function definition
 {
      return l * w;
 }