Extend or trim a polyline feature

The Extend or Trim tool extends or trims polyline features to an existing feature boundary. You can select the features and click a boundary to which you are extending or trimming, or hover over and edit them without a selection. This tool is available in the Modify Features pane.

When you use this tool, consider the following:

• Extending or trimming a z-aware feature preserves the angular pitch of a modified segment and assigns an interpolated or extrapolated z-value to the new vertex.
• If the selected feature is COGO enabled, you can choose to preserve or update COGO attribute values.

To extend or trim a polyline feature, complete the following steps:

1. Add your data and configure settings for editing.

   Confirm that the feature layer you are editing is editable, the coordinate system assigned to the active map is suitable for the type of edits you're performing, and snapping is configured to help you work efficiently and accurately.

2. On the ribbon, click the Edit tab. In the Features group, click Modify .

   The Modify Features pane appears.

3. Click Extend or Trim .

   To find the tool, expand Reshape, or type Trim in the Search text box.

4. Uncheck Allow Extend or Trim without a selection.

   To extend or trim all visible and editable features without creating a selection, check this setting and skip the next step.

5. Click the Select one or more line features tool in the tool pane and select one or more polyline features.

   Tip:

   To refine the selection, right-click a feature in the pane selection tree, and click Unselect or Only Select This .

6. Uncheck Recalculate COGO attributes to preserve existing COGO attribute values.

   Note:

   This setting is only available only if a map contains COGO-enabled feature layers.

   Check Recalculate COGO attributes to update COGO values as described in the following table:

   Straight lines	Circular arcs
   Direction is preserved. Distance is recalculated.	Direction is recalculated. Radius is preserved. ArcLength is recalculated.

7. Choose a tool mode. The type of edit each mode allows you to make is described in the following table:

   Method	Description
   Extend or Trim	Extend or trim polyline features based on the position of the pointer.
   Extend	Only extend polyline features.
   Trim	Only trim polyline features.

8. To extend a selected line feature to a boundary, hover over the feature boundary to which you are extending. When the preview shows the correct edit, click the boundary.

   If Allow Extend or Trim without a selection is checked, hover over the endpoint of the line feature you are extending. When the preview shows the correct edit, click the endpoint.

9. To trim a selected line feature, hover over the feature boundary to which you are trimming. When a dashed-line preview shows the correct edit, click the boundary.

   Note:

   Trimming with a selection automatically chooses the shorter segment. To trim the longer segment, trim without a selection.

   If Allow Extend or Trim without a selection is checked, hover over the part of the line feature that you are trimming. When a dashed-line preview shows the correct edit, click the line feature.