Constrain a point to be incident to any other geometry; line, segment, vector, polygon side, circle or locus with these steps:
| 1. | Select  the point and the other geometry listed above. |
| 2. | Click the Incident icon  from the Constrain toolbox, or select Incident from the Constrain menu. |
The point is moved to meet the line or curve, or the extension of the line.
Below is an example of the latter, point D is moved to lie on the extension of line segment AB.
If you select the point or the line, incidence is indicated by a bowtie around the point:
