how tomade winform from two different winforms

Dear you can yous MDI Form to do like this


try this

   private void toolStripButton2_Click(object sender, EventArgs e)
        {
            Form3 Obj = new Form3();
            Obj.MdiParent = this;
            Obj.Show();
        }

        private void toolStripButton1_Click(object sender, EventArgs e)
        {
            Form2 Obj = new Form2();
            Obj.MdiParent = this;
            Obj.Show();
        }