Available in TurboCAD LTE Pro only
Makes a vertex lie on another vertex, or on another object.
- Start with two lines. Activate the Coincident constraint and select the vertex you want to constrain.
- Select the line which you want the vertex to lie on.
. . . the two vertices will meet. 
- This constraint is similar when using arcs and circles. Start with a line and a circle, and constrain the line endpoint to the arc endpoint.
- If you constrain the vertex to the arc itself . . .
. . . the line joins the arc at the tangent point. 