Drawing Vertical Lines with a T-Square

This illustration shows you how to draw a vertical line, a line perpendicular to the bottom of the page, using a t-square. Notice that the top of the t-square is resting on the edge of the drawing board. Also, notice that the vertical edge of the paper is parallel to the vertical edge of the t-square. This insures that the line you draw will be perpendicular to the bottom of the page.