2013

If the circle was an arc instead, the line or its extension would remain tangent
to the arc or its extension.
The results of modifying underconstrained objects are based on what
constraints have already been applied and the object types involved. For
example, if the Radius constraint had not been applied, the radius of the circle
would have been modified instead of the tangent point of the line.
The CONSTRAINTSOLVEMODE system variable determines the way an object
behaves when constraints are applied or when grips are used to edit it.
BEST PRACTICE You can limit unexpected changes by applying additional
geometric or dimensional constraints. Common choices include coincident and
fix constraints.
Modify Constrained Objects with Editing Commands
You can use editing commands such as MOVE, COPY, ROTATE, SCALE, and
STRETCH to modify constrained geometry. The results maintain the constraints
applied to the objects.
NOTE The TRIM, EXTEND, BREAK, and JOIN commands in some circumstances
can remove constraints.
By default, if an editing command results in copying the constrained objects,
the constraints applied to the original objects will also be duplicated. This
behavior is controlled by the PARAMETERCOPYMODE system variable. Using
the copying technique, you can save work by taking advantage of multiple
instances of objects, bilateral symmetry, or radial symmetry.
For information about temporarily relaxing constraints, see
Overview of
Constraints
(page 282).
292 | Chapter 6 Create and Modify Objects