type
  TShape = class
  public
    LineCount: Integer;
    constructor Create(ALineCount: Integer);
  end;

  TSquare = class(TShape)
  public
    SideLength: Integer;
    constructor Create(ASideLength: Integer);
  end;

constructor TShape.Create(
  ALineCount: Integer);
begin
  LineCount := ALineCount;
end;

constructor TSquare.Create(
  ASideLength: Integer);
begin
  inherited Create(4);
  SideLength := ASideLength;
end;

var
  Square: TSquare;
begin
  Square := TSquare.Create(5);
  //square.LineCount is 4

  WriteLn('lineCount is ', Square.LineCount);
end.