Patterns consist of repeated elements. One of the most common spatial patterns that we experience and use are shapes. For example, a simple shape like a square contains repeated elements - a side and a right angle, repeated 4 times. Children's reasoning about shape generally follows a predictable sequence. Awareness of this typical sequence helps adults understand how a child's growth is progressing and what to expect next.
Children begin to reason about shape by resemblance.
In other words, unfamiliar shapes are identified by their resemblance to familiar shapes. As children develop a vocabulary about shape, they begin to view shapes as having characteristics or attributes. When children first reason about attributes, they often don't make connections among them. As children solve problems, they begin to coordinate attributes, so that if a closed shape has four sides, then they also know that it has four angles. When children reason about shapes via resemblance or attributes, their thinking is guided primarily by what they see.