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For example, if a line object is constrained to remain tangent to a circle, you
can rotate the line and change its length and endpoints, but the line or its
extension will remain tangent to the circle.
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.
728 | Chapter 19 Add Constraints to Geometry