### opdracht 2 ###

### activity_main.xml ###

<androidx.constraintlayout.widget...>
  
    ...

    <Button
        android:id="@+id/button3"
        android:layout_width="180dp"
        android:layout_height="50dp"
        android:layout_marginTop="60dp"
        android:text="1-responsive"
        app:layout_constraintTop_toBottomOf="@+id/button2"
        tools:layout_editor_absoluteX="0dp"
        android:onClick="start1_responsive"/>

    ...

</androidx.constraintlayout.widget.ConstraintLayout>

### MainActivity.java ###

public class MainActivity extends AppCompatActivity {

    ...

    public void start1_responsive(View view){

        Intent browserIntent = new Intent("android.intent.action.VIEW",
        Uri.parse("https://dequeuniversity.com/library/responsive/1-responsive"));
        startActivity(browserIntent);

    }
  
    ...

}