Entering New Dimensions - AutoCAD 2012 - page 331

Linear dimensions are the most common type of dimensions, and horizontal and vertical
are the most common of those. The following example demonstrates all the important
techniques for creating horizontal and vertical linear dimensions, as well as aligned di-
mensions (which are similar to linear dimensions):
1. Use the LINE command to draw a non-orthogonal line — that is, a line segment
that's not horizontal or vertical.
An angle of about 30 degrees works well for this example.
If you want to apply dimensioning to an object other than a line, use these steps as
a general guideline, filling in the appropriate commands and data as applicable to
your drawing.
2. Set a layer that's appropriate for dimensions as current.
Just as with text, it's a good idea to have a dedicated layer for dimensions in every
drawing. See Chapter 6 for details on setting a layer as current.
3. Set a dimension style that's appropriate for your needs as current.
Choose an existing dimension style from the Dimension Style drop-down list on the
Annotation panel slideout on the Ribbon's Home tab, or create a new style by using
the procedure in the section “Creating and managing dimension styles,” earlier in
this chapter.
4. On the Annotate tab's Dimensions panel, click the lower half of the Di-
mension split button and choose Linear, or type DLI and press Enter.
AutoCAD prompts you:
Specify first extension line origin or <select object>:
5. To specify the origin of the first extension line, snap to the lower-left endpoint of
the line by using endpoint object snap.
If you don't have endpoint as one of your current running object snaps, specify a
single endpoint object snap by holding down the Shift key, right-clicking, and
choosing Endpoint from the menu. (See Chapter 7 for more about object snaps.)
AutoCAD prompts you:
Specify second extension line origin:
6. To specify the origin of the second extension line, snap to the other endpoint of
the line by using endpoint object snap again.
AutoCAD draws a horizontal dimension — the length of the displacement in the left-
to-right direction — if you move the crosshairs above or below the line. It draws a
vertical dimension — the length of the displacement in the up-and-down direction
— if you move the crosshairs to the left or right of the line.
AutoCAD prompts you:
Specify dimension line location or