You can add fixed, floating, or free tangents and curves to a layout profile.
Use constraint-based commands on the Profile Layout Tools toolbar to refine the layout profile design to meet your project objectives.
Note: When drawing or editing constraint-based profile entities, ensure that the Profile Layout Tools toolbar is set to 
Entity Based mode.
Entity Based mode. The three entity type describes the way an entity is defined and edited:
- Fixed entities are defined by specifying parameters, such as pass-through points, tangent slope, and curve radius. The entities are fixed in position and must be edited directly. Except for its length, the geometry of a fixed entity is not dependent on adjacent entities. If an adjacent entity is edited, the geometry of the fixed entity is not affected.
- Floating entities are defined by specifying parameters and an entity to attach to. Floating entities are always tangent to the entity they are attached to, and are dependent on the other entity to define their geometry.
- Free entities are defined by attachment to two entities, before and after. The free entity always remains tangent to the two adjacent entities, and its geometry is defined by these adjacent entities.