Answer:
Here is the GamePoints constructor:
GamePoints::GamePoints() : 
/* Your code goes here */
 { 
teamLions = 500;
teamDolphins = 500; 
 }     
Explanation:
Here is the complete program:
#include  //to use input output functions
using namespace std; //to identify objects like cin cout
class GamePoints {  //class GamePoints
    public: GamePoints(); // constructor of GamePoints class
    void Start() const;  //method of GamePoints class
    private: //declare data members of GamePoints class
    int teamDolphins; // integer type private member variable of GamePoints 
    int teamLions; }; // integer type private member variable of GamePoints 
    GamePoints::GamePoints()  //constructor
     { teamLions = (500), teamDolphins= (500); }   //assigns 500 to the data members of teamLions  and teamDolphins of GamePoints class
    void GamePoints::Start() const    { //method Start of classs GamePoints
        cout << "Game started: Dolphins " << teamDolphins << " - " << teamLions << " Lions" << endl; }  //displays the values of teamDolphins and teamLions i.e. 500 assigned by the constructor
        int main() //start of main() function
        { GamePoints myGame;  // creates an object of GamePoints class
        myGame.Start(); //calls Start method of GamePoints class using the object
        return 0; }
The output of the program is:
Game started: Dolphins 500 - 500 Lions