Polygonal chain

A polygonal chain is like the line you draw when you connect a bunch of dots together. You start at one dot and go to the next one, and then the next one, and so on, until you've connected all the dots. Each time you go to a new dot, you make a straight line. So the polygonal chain is a bunch of straight lines that connect the dots. The chain doesn't have to make a complete shape like a square or triangle, it can just be a bunch of lines going in different directions.