FactBook and getFact are underlined red: Cannot resolve?

private FactBook mFactBook = new FactBook();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_fun_facts);
    // Declare our view variables and assign views

    final TextView factLabel = (TextView) findViewById(R.id.factLabel);
    Button showfactbutton = (Button) findViewById(R.id.showfactbutton);
    View.OnClickListener listener = new View.OnClickListener() {
        @Override

        public void onClick(View view) {
        String fact = mFactBook.getFact();

            //Update label with dynamic fact
            factLabel.setText(fact);

        }
    };
    showfactbutton.setOnClickListener(listener);

}

//Methods - things the object can do
   public String[] mFacts = {
            "Ants stretch when they wake up in the morning.",
            "Ostriches can run faster than horses.",
            "Olympic gold medals are actually made mostly of silver.",
            "You are born with 300 bones; by the time you are an adult you will have 206.",
            "It takes about 8 minutes for light from the Sun to reach Earth.",
            "Some bamboo plants can grow almost a meter in just one day.",
            "The state of Florida is bigger than England.",
            "Some penguins can leap 2-3 meters out of the water.",
            "On average, it takes 66 days to form a new habit.",
            "Mammoths still walked the earth when the Great Pyramid was being built." };

    // Stuff that will happen when clicked
    //Button was clicked so update fact

    public String getFact(){

        String fact = "";

    //randomly select fact
    Random randomGenerator = new Random(); // construct a new random number generator
    int randomNumber = randomGenerator.nextInt(mFacts.length);

    fact = mFacts[randomNumber];

    return fact;