Constrains two curves to maintain a point of tangency to each other or their extensions.
Access Methods
Button
Toolbar: Drafting tool set 
Parametric tool group Geometric Constraints flyout Tangent Menu:
Parametric
Geometric Constraints
Tangent
Summary
This command is equivalent to the Tangent option in GEOMCONSTRAINT.
Following are the valid constraint objects and points:
- Line
- Polyline segment
- Circle, arc, polyline arc, ellipse
- Combination of circles, arcs, or ellipses
A circle can be tangent to a line even if the circle does not touch the line. A curve can be tangent to another even if they do not physically share a point.