Binary Relation 

Consider the set B = { Albert Einstein, Queen Victoria, David Beckham, Florence Nightingale } and the relation "is the same gender as".
Then Albert Einstein * David Beckham and David Beckham * Albert Einstein. Similarly Albert Einstein * Albert Einstein !!!
A further example, consider $Z$ , the set of integers. The relation "is greater than" would define such ordered pairs as ( 7, 4) and (6, 12).
Question: Which person in the set B developed a type of pie chart? Clue: It wasn't Albert Einstein.