Venn diagrams with three circles compare the intersection of three separate concepts. Create a Venn diagram with three circles by drawing two overlapping circles and then a third circle that intersects the other two with its edge about halfway through the original intersect point. This should leave four areas in which the circles overlap, only one of which should include all three circles.
Use Venn diagrams with three circles to compare overlapping concepts or qualities. For example, a three-circle Venn diagram may compare the intersection of intimacy, commitment and passion, as in the triangular theory of love, or it may tally votes from a multiple choice question, such as "What music do you like?" The middle section contains all three circles and thus all three qualities, while the other three sections only contain the qualities of two of the given circles. The remaining sections represent only the lone quality the diagram states them to represent.
The Venn diagram was named after John Venn, an English logistician, who made them as an argument in favor of the expression of relations between objects or qualities in effectively algebraic terms, defending another philosopher's work. Venn diagrams, which are now used in displays as early as grade school, have passed into the public consciousness.