Which diagram uses two overlapping circles to show similarities and differences between sets?

• A. Bar chart
• B. Circle diagram
• C. Venn diagram
• D. Pie chart

Answer: (C)

Think about how we show relationships between groups. A diagram with two circles that overlap is designed to display what each group has in common and what each one has that the other doesn’t. The overlapping part shows elements that belong to both sets (similarities), while the non-overlapping parts show elements unique to each set (differences). That exact idea is what a Venn diagram does when comparing two sets. A bar chart uses bars to compare quantities, not the overlap of groups. A circle diagram isn’t specifically about comparing two sets, and a pie chart shows parts of a whole as slices, not the relationship between two groups.