Robert Yates wrote a book exploring approximations like this and other means of trisection (graduated ruler, linkages, etc.). https://www.google.com/#q=the+tri

Robert Yates wrote a book exploring approximations like this and other means of trisection (graduated ruler, linkages, etc.). https://www.google.com/#q=the+trisection+problem+yates https://www.google.com/#q=the+trisection+problem+yates