The Lines and Curves command in Civil 3D is a powerful tool for creating and editing 2D and 3D lines, curves, and polylines. Here's an overview of how to work with this command:

Creating Lines and Curves:

1. Start the command: Select the "Lines and Curves" command from the "Draw" menu or use the shortcut "LC".
2. Choose a method: Select from various creation methods, such as "Point, Point", "Point, Angle", or " Curve".
3. Specify points: Enter points to define the line or curve.
4. Add vertices: Add additional vertices to create a polyline.

Editing Lines and Curves:

1. Select the object: Choose the line or curve to edit.
2. Use grips: Use grips to move, add, or remove vertices.
3. Edit vertices: Use the "Edit Vertex" option to modify individual vertices.
4. Change properties: Modify properties like layer, color, or linetype.

Tips and Tricks:

- Use the " Curve" option to create smooth curves.
- Hold "Ctrl" while selecting points to create a straight line.
- Use the "Close" option to create a closed polyline.
- Experiment with different creation methods and editing techniques.

Some popular searchable keywords related to working with the Lines and Curves command in Civil 3D include:

- "Civil 3D Lines and Curves tutorial"
- "Create lines and curves in Civil 3D"
- "Edit lines and curves in Civil 3D"
- "Civil 3D curve creation"
- "Civil 3D polyline editing"