private void mnuMaterias_Click(object sender, EventArgs e)
        {
            frmMaterias frmMaterias = new frmMaterias(persona);

            frmMaterias.MdiParent = this;
            frmMaterias.Show();
        }
 private void mnuMaterias_Click(object sender, EventArgs e)
 {
     frmMaterias frmMaterias = new frmMaterias(persona);
     frmMaterias.MdiParent = this;
     frmMaterias.Show();
 }