I have an old friend who has been a recovering alcoholic for 46yrs. he says when he went for help his blood cells were square is this possible?

No!: Many alcoholics have larger red blood cells from nutritional deficiencies. Maybe he misunderstood that information.

Not exatly: Normal red cells are biconcave discs. They can be bent into many unusual shapes which are associated with disease such as chronic alcohol use. Some of these have fanciful names such as: burr cells, helmet cells, target cells, bite cells, teardrop cells, sickle cells, but none of them are square. A square shape would require too much energy to maintain.