By the Unit or Square Unit?
Bellasanta B. Ferrer, Bobbie Hunter, Kathryn C. Irwin, Maureen J. Sheldon, Charles S. Thompson, and Catherine P. Vistro-Yu
November 2001, Volume 7, Issue 3, Page 132
Three ways in which teachers help their students understand that the most compact two-dimensional shape has the greatest area for a given perimeter.
Perimeter / Circumference
Reasoning and Proof