The Line Tool can be used as a ruler for basic measuring. It can also be used to ping people or locations on the board.
If you have the Line Tool (F5) selected and just click your LMB over and over, there will be an arrow and a “ping” sound. You want to use this when it’s someone’s turn and you’re trying to get their attention. Or if someone isn’t sure where to put something down, you can “ping” the location to them so they know where it’s supposed to go. You can use the ping arrow any time by just holding TAB and clicking – so you don’t need to be in the Line Tool menu.
The Line Tool is also used as a ruler to measure distances between objects if needed. Our ruler uses inches for measuring and the numbers are shown where your mouse is pointing to.