Answer:
Step-by-step explanation:
Think of your family tree. It consists of your brothers, sisters, cousins, second cousins,
aunts uncles, parents grandparents, great grandparents etc. On this set of relatives there
is defined a relation (ship), that is, person a appears above person b in your family tree if
and only if person a is an ancestor of person b. Think of an ancestor, say your great grandmother,
and picture your family tree diagram with her listed at the top of the page and all her descendants
listed below. This is an example of a “mathematical” diagram or graph called a tree or a
partial ordering diagram. The ordering is called partial because, for example, you and your
siblings and your cousins are all on the same level. Note there is a direction in this graph,
namely from the top down so this is a directed graph.
