Journal of the Mathematics Council of the Alberta Teachers’ Association
Volume 27 Issue 3, April 1989
30 – 36
There Are No Holes Inside a Diamond
Mogens Esrom Larsen
There are twelve different ways of putting together five unit squares edge-to-edge. The results are the Pentominoes. (Pentomino is a registered trademark of Solomon W. Golomb who introduced them (Golomb 1954).) They are shown in Figure 1-1 with their single-letter names.