Which type of graph uses percentages to display its data?

A pie chart is specifically designed to display data in terms of percentages, providing an immediate visual representation of how different parts contribute to a whole. Each slice of the pie corresponds to a specific category, and the size of the slice reflects its proportion relative to the total. This makes pie charts particularly effective for showing the distribution of categorical data, such as market share or survey results, where the emphasis is on the relative size of each part.

Bar graphs and histograms, although useful for comparing quantities, typically represent absolute values rather than percentages. Line graphs are primarily used to illustrate trends over time and would not appropriately display data in percentage form. Thus, the defining characteristic of a pie chart is its focus on presenting data as proportions of a whole, making it the correct choice for this question.