2011

Table Of Contents
As you can see, part of the equation for determining the area of the circle is
included in the Radius dimensional constraint parameter and part was defined
as a user variable. Alternatively, the entire expression, sqrt (Length * Width /
PI), could have been assigned to the Radius dimensional constraint parameter,
defined in a user variable, or some other combination.
Protect Expressions in Dynamic Constraints
When a dynamic dimensional constraint references one or more parameters, the
prefix fx: is added to the name of the constraint. This prefix is displayed only
in the drawing. Its purpose is to help you avoid accidentally overwriting
parameters and formulas when the dimension name format is set to Value or
Name, which suppresses the display of the parameters and formulas.
Quick Reference
PARAMETERS
Controls the associative parameters used in the drawing.
-PARAMETERS
Controls the associative parameters used in the drawing.
Control Geometry with the Parameters Manager
The Parameters Manager displays dimensional constraint parameters (both
dynamic constraints and annotational constraints), reference parameters, and
user variables.
NOTE This topic has been included for AutoCAD-compatibility purposes only. In
AutoCAD LT, parametric drawing technology is limited to displaying and hiding
constraints, editing constrained geometry, and changing values in the Parameters
Manager.
You can easily create, modify, and delete parameters from the Parameters
Manager.
The Parameters Manager supports the following operations:
Click the name of a dimensional constraint parameter to highlight the
constraint in the drawing.
Double-click a name or expression to edit it.
646 | Chapter 18 Add Constraints to Geometry