Figure 63 is a three-quarters perspective photograph of a rectangular shaped object. Using the width as a basis for measurement, it looks to be about twice as deep as it is wide and four times as long as it is wide. The outer surface has contours, indentations and protuberances. At one end there is an additional structure on one side making it twice as wide as the rest of the object. The top surface of the object is smooth and flat. There is a line of 6 relatively large vertical holes along the length of the object. On either side of these holes there is a single vertical cavity running the length of the object that curves around each of the central holes. There is a major vertical cavity traversing the width of the object at the wider end. A number of other vertical holes are evident in the top surface of the object.

 4.2.3 Classifying shapes