Membuat Aplikasi Luas Segitiga

public class MainActivity extends AppCompatActivity {
    Double alas,tinggi,luas;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }
    public void hitung (View view) {
        EditText edtAlas = (EditText)findViewById(R.id.edtAlas);
        EditText edtTinggi = (EditText)findViewById(R.id.edtTinggi);
        TextView txtHasil = (TextView)findViewById(R.id.txtHasil);
        alas = Double.parseDouble(edtAlas.getText().toString());
        tinggi = Double.parseDouble(edtTinggi.getText().toString());
        luas = alas*tinggi/2;
        txtHasil.setText("Luas segitiga = alas x tinggi = " + luas);
    }
}