VENN Diagram

If one item belongs to the class of second and the third item is partly related to the second, they
are represented as shown alongside.
Ex. Males, Fathers, Children
Clearly, all fathers are males. This would be represented by two concentric circles. But, some
males are children. But, children cannot be fathers. Thus, the diagram becomes as shown in
figure 9 with circle A representing Fathers, circle B representing Males and circle C representing
Children.