How to used a circular saw to cut a straight edge without a table saw. Not all of us have a table saw in our garage. Or even if we did you can’t always use it if you needed to cut a 4×8 sheet of plywood.
For this reason you would follow this video using a completely straight, straight edge. You can either use a level, straight board or what I like to use is a piece of metal. For a few bucks you can pick one of these up at the home store in the hardware section.