What type of graph uses vertical rectangles to represent data?

A bar graph employs vertical rectangles, or bars, to visually represent data. Each bar's height corresponds to the value it represents, allowing for easy comparison between different categories or groups. The choice of using vertical rectangles makes it straightforward to see differences in magnitude across the various categories being analyzed. This format is particularly effective for categorical data, where individual bars can represent distinct groups or classes.

In contrast, a scatterplot displays data points as dots on a two-dimensional coordinate system, which is useful for showing relationships between two continuous variables. A dot plot represents individual data points using dots along a number line, giving a clear representation of distribution but not using rectangles. A pie chart shows parts of a whole in a circular format, which does not utilize bars at all. Thus, the distinctive feature of the bar graph is its use of vertical rectangles, making it the correct choice for this question.