There are several methods you can use to reduce the length of a line. Which one to use depends on how many lines you want trimmed at a time and whether you want the line trimmed to a specific length, a line you draw, or based on an intersection with an existing line. The main ways you can trim a line are by using the Trim command on the Sketch context menu; the Extend/Trim edit task; or the Trim tool on the Advanced Editing toolbar.

You can also trim line features that violate a "Must not have dangles" topology rule with the Trim option of the Fix Topology Error tool.

The Extend/Trim edit task lets you select a line and trim it where you sketch a line. The line is trimmed on the right side of the line you sketch. In this example you see how to use the Extend/Trim Features edit task to trim a selected line. The part of the line to the right of the sketch (within the building polygon) is removed.