This tool adds a tangent constraint between two arcs or a line and an arc.
To use the tool, identify the required entities. The entities will then be constrained so that remain tangential to each other.
Alternatively, you can select the two entities and then start the tool. The tangent constraint will then be added to the selected lines.
After creating the tangent constraint you can hover your cursor over the constraint and the related entities will be highlighted.
NOTE: Whilst this tool can be used to move entities so as to satisfy the constraint, it is recommended that entities are created in the desired position.