Use a T-square to draw straight, horizontal lines and to provide support for
triangles when you draw lines at an angle. The two parts of a T-square are
the blade and the head. The blade comes in different lengths and has a hole
in the far end for hanging the T-square up for storage. The most popular
blade length is 36 inches. The head mounts under the blade at a 90-degree
angle and rests against the table edge. It guides the T-square in an up-and-
down movement on the drawing surface. Because a T-square allows very
little adjustment when it is damaged or out of true, throw it away and get
Figure 2-15 shows a T-square positioned on a drawing board.
Figure 2-15. A t-square on a
Figure 2-16 illustrates the direction for drawing horizontal lines against a
T-square or straightedge.
Figure 2-16. Drawing
horizontal lines with at-
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