Why am I getting a "board not declared" error when I am trying to pass it as a parameter? (C++)

Question

Example of the codeFairly new to object oriented programming. I am trying to make a connect 4 game with a class for the overall game, which contains a board object which then contains two player objects. I've realized that I need my players to be able to access some information from the board, specifically row and column lengths (also using pointers so the user can edit the board size), so I was trying to pass a board object to those specific functions as a parameter. I'm getting the undeclared error stated above but I'm just confused on why I would need to declare it in player class when I'm only using it as a parameter.

For example I get this error: error: 'board' has not been declared 25 | int takeTurn(board& myBoard); | ^~~~~

Here's some of the code from my player.h file:

#ifndef PA02_TEMPLATE_PLAYER_H
#define PA02_TEMPLATE_PLAYER_H


#include "board.h"

class player{
private:
protected:
    char piece;
    int playerMove[2];
    int playerNum;
public:
    player()= default;

    player(char p, int num){
        piece = p;
        playerNum = num;
    }

    int takeTurn(board& myBoard);

    void colChoice(int i);

    void findRow(board& myBoard, int rows);

    void setPlayerNum(int i){
        playerNum = i;
    }
    void setPiece(char p){
        piece = p;
    }

    char getPiece(){
        return piece;
    }

    int getPlayerNum(){
        return playerNum;
    }




};
class aiPlayer : player{
private:
    int aiDifficulty = 2;
public:
    void setDifficulty(int i){
        aiDifficulty = i;
    }
    int getDifficulty(){
        return aiDifficulty;
    }
    void takeTurn(int rows, int COLS, board& myBoard);

    vector<int> minimax(board& miniBoard, int depth, int alpha, int beta, bool maximizingPlayer);
    int scorePosition(char piece, char opponents_piece, board& scoringBoard);
};

#endif //PA02_TEMPLATE_PLAYER_H