How do you put a ruler on your screen for 8 ball pool?

To put a ruler on your screen for 8 Ball Pool, you can use a screen ruler tool or overlay software. Many apps allow you to measure distances on your screen by displaying a ruler that you can drag and position. Simply download and install a suitable tool, then follow its instructions to enable the ruler overlay. Make sure to adjust the ruler's position as needed while playing to assist with your shots.