private void toolStripMenuItemOpen_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog1 = new OpenFileDialog();

            openFileDialog1.Filter = "Triangle or Circle file (*.crcl;*.tri)|*.crcl;*.tri|Circle file (*.crcl)|*.crcl|Triangle file (*.tri)|*.tri";
            openFileDialog1.Title  = "Open a Circle or Triangle File";
            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                if (System.IO.Path.GetExtension(openFileDialog1.FileName) == ".crcl")
                {
                    FormCircleView childForm = new FormCircleView(this, openFileDialog1.FileName);
                    if (childForm.FileName == null)
                    {
                        childForm.Dispose();
                    }
                    else
                    {
                        childForm.Show();
                    }
                }
                else if (System.IO.Path.GetExtension(openFileDialog1.FileName) == ".tri")
                {
                    FormTriangleView childForm = new FormTriangleView(this, openFileDialog1.FileName);
                    if (childForm.FileName == null)
                    {
                        childForm.Dispose();
                    }
                    else
                    {
                        childForm.Show();
                    }
                }
            }
        }
        private void newCoinToolStripMenuItem_Click(object sender, EventArgs e)
        {
            // Declare the child form as a new one.
            FormCircleView childForm = new FormCircleView();

            // Set the main form as a parent form.
            childForm.MdiParent = this;
            // Show the child form.
            childForm.Show();
        }