Datasheet

LENGTHEN
This interesting command can be used to change the length of a line, polyline, or an arc. It’s
the only way to quickly create an arc with a specific arc length. To do that, create the arc,
and use the Total option of LENGTHEN to change the total length to whatever you want.
LENGTHEN’s options include the following:
DElta DElta allows you to add a specific amount to the length of an existing line or arc, or
to add a specific angle to the existing included angle of an arc.
Percent Percent allows a specific percentage increase in the length of a line or pline or the
included angle of an arc.
Total Total lets you set a new overall length for a line, a pline, or an arc.
DYnamic DYnamic allows you to change the length of a line (but not a pline) or the
included angle of an arc by picking a new point and watching it change.
<Select object> <Select object> gives the existing length or angle of a line or arc.
Dimensions
Dimension styles are discussed at length in Chapter 4 because they’re critical to applying
technical graphics standards correctly. Here I want to point out some aspects of the
process of dimensioning that people often get wrong, starting with a difference that almost
nobody seems to understand: aligned versus rotated dimensions
Aligned vs. Rotated
In my experience, most users don’t understand rotated dimensions. All linear dimensions
are either aligned or rotated, but most are rotated. Vertical dimensions are rotated to 90,
horizontal dimensions to 0. Because those angles are
built in, users often overlook the possibility of rotating
dimensions to other angles and frequently attempt to
use an aligned dimension where a rotated one is needed.
Figure 1.19 shows the problem with trying to use
DIMALIGN.
To place a rotated linear dimension between two
points at any angle, use DIMLINEAR and select the
Rotated option. You can specify a rotation angle
directly or by picking any two points that are at the
desired angle of rotation.
30 ■ chapter 1: AutoCAD Productivity
Figure 1.19
Rotated dimensions
versus aligned
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