}       // radioBtn_RectangleRod_CheckedChanged

        void radioBtn_RectangleTube_CheckedChanged(object sender, EventArgs e)
        {
            if (radioBtn_RectangleTube.Checked == true)
            {
                profile = Profile.RectangleRing;
                //pict_01.Image = CalcStress_001.Properties.Resources.RectangleTube;
                pict_01.Image   = CalcStress_003.Properties.Resources.rect_rad;
                TBox_1.name1    = "B, mm";
                TBox_2.name1    = "H, mm";
                lbl_TBox_1.Text = TBox_1.name1;
                lbl_TBox_2.Text = TBox_2.name1;
                TBox_2.Show();
                lbl_TBox_2.Show();
                TBox_3.Show();
                lbl_TBox_3.Show();
                if ((radioBtn_Twist.Checked == true) || (radioBtn_Cut.Checked == true))
                {
                    radioBtn_Stretch.Checked = true;
                }
                radioBtn_Twist.Enabled         = false;
                radioBtn_Cut.Enabled           = false;
                radioBtn_RectangleTube.TabStop = false;
                TBox_10.Text = "";
                TBox_11.Text = "";
                Result_1_Clear();
                Result_2_Clear();
                TBox_1.Focus();
            }   // if (radioBtn_RectangleRod.Checked == true)
        }       // radioBtn_RectangleTube_CheckedChanged
        // Профиль

        void radioBtn_CircleRod_CheckedChanged(object sender, EventArgs e)
        {
            if (radioBtn_CircleRod.Checked == true)
            {
                profile         = Profile.Circle;
                pict_01.Image   = CalcStress_003.Properties.Resources.CircleRod;
                TBox_1.name1    = "D, mm";
                lbl_TBox_1.Text = TBox_1.name1;
                TBox_2.Hide();
                lbl_TBox_2.Hide();
                TBox_3.Hide();
                lbl_TBox_3.Hide();
                radioBtn_Twist.Enabled     = true;
                radioBtn_Cut.Enabled       = true;
                radioBtn_CircleRod.TabStop = false;
                TBox_10.Text = "";
                TBox_11.Text = "";
                Result_1_Clear();
                Result_2_Clear();
                TBox_1.Focus();
            }   // if (radioBtn_CircleRod.Checked == true)
        }       // radioBtn_CircleRod_CheckedChanged