 In this case, the drafter places one or more triangles of known angles on the T-square—which is itself at right angles to the edge of the table—and can then draw lines at any chosen angle to others on the page.Modern drafting tables come equipped with a drafting machine that is supported on both sides of the table to slide over a large piece of paper.Because it is secured on both sides, lines drawn along the edge are guaranteed to be parallel.