Dimensioning a Drawing - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 624

NOTE Most of the commands used for dimensioning are prefaced
with DIM when you enter them at the command line; that is, DIM is part
of the command name. For example, when you click the radius button
on the annotate tab ➢ Dimensions panel or Dimension toolbar, you see
_DIMRADIUS in the command window to let you know that you have started
the DIMRADIUS command. You can also start this command by entering
DIMRADIUS ↵ or DRA ↵ (the command alias).
FiGuRE 12.33 The radius dimension initially positioned on the curve
The radial dimension you just inserted uses the same architectural tick the
other linear dimensions in your drawing use. Typically, an arrow, not an architec-
tural tick, would be used to illustrate radial dimensions. To fix this, you will need
to create a Child Dimension style. You'll learn how to create parent and child
dimension styles at the end of this section, under “Setting Up Parent and Child
Dimensioning Styles.”
Adding a Diameter Dimension
Similar to the radius dimension, a diameter dimension measures the distance
from one side of a circle or arc, through the center point, to the other end.
Follow these steps to place a diameter at the filleted corner:
1. Erase the radius dimension.
2. Click the arrow below the Radius button on the Dimension panel
within the Annotate tab, and then click the Diameter button to start
the DIMDIAMETER command.
3. Click the inside filleted corner near the location where it meets the
vertical wall.
The diameter dimension appears, and the text is attached to the cursor.
4. Click to place the radius text in the dimension. The ∅ prefix indicates
that this is a diameter dimension. Where you pick on the curve deter-
mines the angle of the radius dimension (see Figure 12.34).