private void comboBox1_SelectedIn dexChanged object sender EventArgs s

private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            switch (comboBox1.SelectedIndex)
            { 
                case 0:
                    points = new Point3D[4];

                    points[0] = new Point3D(250, 150, 400);
                    points[1] = new Point3D(250, 350, 400);
                    points[2] = new Point3D(450, 350, 200);
                    points[3] = new Point3D(450, 150, 200);

                    newGraphics.Clear(Color.White);
                    draw_rectangle();

                    break;

                case 1:
                    points = new Point3D[8];

                    points[0] = new Point3D(250, 150, 400);
                    points[1] = new Point3D(250, 350, 400);
                    points[2] = new Point3D(450, 350, 200);
                    points[3] = new Point3D(450, 150, 200);
                    points[4] = new Point3D(50, 150, 400);
                    points[5] = new Point3D(50, 350, 400);
                    points[6] = new Point3D(250, 350, 200);
                    points[7] = new Point3D(250, 150, 200);
                    double N = 0.66;
                    for (int i = 0; i < 8; i++)
                    {
                        points[i] = new Point3D((int)(points[i].X * N), (int)(points[i].Y * N), (int)(points[i].Z * N));
                    }
                    newGraphics.Clear(Color.White);
                    draw_cube();

                    break;
            }
        }