Relationships cannot be maintained in certain cases, as in the following example.

1. Choose Arc By 3 Points.

2. Click where you want the sweep of the arc to begin (A).

3. Move the cursor to a position where IntelliSketch recognizes a point on element relationship with a line on the drawing sheet (B).

4. When the Point On IntelliSketch relationship indicator is displayed at the cursor, click to define the second input point for the arc.

5. Move the cursor past the line and click (C). The position of this input point defines it as the end of the sweep, making the point in the middle an unconstrainable key point. IntelliSketch recognizes this, and does not maintain the point on element relationship.

If the third input point for the arc had been between the first two points, then it would have been interpreted as the arc midpoint, making the second input point one end of the arc sweep. In this case, the point would have been constrainable, and IntelliSketch would have maintained the point on element relationship.