I added \threecolumn but it doesn't work.
What command will change the document layout to three column format with dividers visible like the following illustration?
---------HEADER---------
###### | ###### | ######
###### | ###### | ######
###### | ###### | ######
###### | ###### | ######
###### | ###### | ######
###### | ###### | ######
---------FOOTER---------


\linewidthor\columnwidth(or ask a question that shows the problem adding images). – cabohah Aug 25 '23 at 06:04\documentclass[twocolumn]{article}– MadyYuvi Aug 25 '23 at 06:08multicol– MadyYuvi Aug 25 '23 at 07:07