2012

For example, you can specify that a line should always be perpendicular to
another one, that an arc and a circle should always remain concentric, or that
a line should always be tangent to an arc.
When you apply a constraint, two things occur:
■ The object that you select adjusts automatically to conform to the specified
constraint
■ By default, a gray constraint icon displays near the constrained object as
shown in the previous illustration, and a small blue glyph displays with
your cursor when you move it over a constrained object
Once applied, constraints permit only those changes to the geometry that do
not violate the constraints. This provides a method for exploring design options
or making design changes while maintaining the requirements and
specifications of the design.
NOTE The order in which you select two objects when you apply a constraint is
important in some cases. Normally, the second object you select adjusts to the
first object. For example, when you apply a perpendicular constraint, the second
object you select will adjust to become perpendicular to the first.
720 | Chapter 19 Add Constraints to Geometry