Once upon a time there was a college professor named A Squared. A Squared lived in Flat Land. Everything in Flat Land had just two dimensions: height and breadth. Nothing in Flat Land had any depth! The people lived in flat houses, ate flat meals, drank flat colas, thought flat thoughts and lived flat lives. Everything was flat. If a person turned sideways, you could not even see that individual!

A Squared taught mathematics at the local university. One night he threw a party for some of his colleagues on the faculty. Upstairs his precocious little son, Pentagon, tried to sleep. As the little boy tossed fitfully, he began to dream. In his dream Pentagon imagined that he was suddenly in a world where everything had not only height and breadth, but depth as well. What a difference that made! …