shape
Source:
Battista (2007) Individuals form scan paths that enable them to recognize similar perceptual objects (e.g. triangles that look approximately the same). When several different types of triangular perceptual objects are abstracted and associated with the word triangle, an early conceptualization of triangle is created. However, at this early stage of recognition, an individual's "conceptualization" of triangle is usually limited to a small set of prototypes and is holistic in nature (p 856-7).