Fragment with drawermenu in action toolbar

Question

The problem is the following I have my main activiy that consists of a drawer activity when I give some of the options of the drawer activity I have to pass to a fragment, the problem is the following when I pass to the fragment I lose the option to open the menu From the drawer from the fragment

`

import android.os.Bundle;
import android.support.v4.app.FragmentManager;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);


        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.setDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);
    }
@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);`

This is the main activity java code

This is the fragment code where I want to implement the drawer

public class Fragmen1 extends Fragment {

   Button HBoton;
   Button GBoton;
   Button SCTBoton ;
   Button RGboton ;
   Button CPBoton ;
   Button ARBoton;


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        View view = inflater.inflate(R.layout.fragment_fragmen1, container, false);


        HBoton = (Button) view.findViewById(R.id.HipotenusaBoton);
        HBoton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {


                Intent HBoton = new Intent(getActivity(), Hipotenusa.class);
                startActivity(HBoton);
            }
        });



         GBoton= (Button) view.findViewById(R.id.button3);
        GBoton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {


                Intent GBoton = new Intent(getActivity(), Grados_Radianes.class);
                startActivity(GBoton);
            }
        });



        SCTBoton = (Button) view.findViewById(R.id.SCTboton);
        SCTBoton.setOnClickListener(new  View.OnClickListener() {


            @Override
            public  void  onClick (View v ){



                Intent SCTBoton = new Intent(getActivity(), SenoCosenoTangente.class);
                startActivity(SCTBoton);
            }
        });

        RGboton = (Button) view.findViewById(R.id.button6);
        RGboton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                Intent RGboton = new Intent(getActivity(),RadianesGrados.class);
                startActivity(RGboton);
            }
        });


        CPBoton = (Button) view.findViewById(R.id.CAPbutton);
        CPBoton.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {

                Intent CPBoton = new Intent( getActivity(),CordenadasRectagularesPolares.class);
                startActivity(CPBoton);
            }
        });

        ARBoton = (Button) view.findViewById(R.id.arboton);
        ARBoton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Intent ARBoton = new Intent( getActivity(),AnguloReferencia.class);
                startActivity(ARBoton);

            }
        });

        return  view;

    }

}