This is another little known tool that has its uses in certain situations. This trim tool allows you to trim lines or polylines between two other lines or polylines, and you can specifically choose which lines you wish to trim to. This tool works with both lines and polylines.
To use this tool:
1. Click on the tool (shown above).
2. Click on the lines which are to be trimmed—they will highlight blue.
3. Right-click to end the selection process.
4. Click the lines you wish to trim between.
5. Right-click to complete the trim process.