There are three main kinds of shapes. Geometric shapes are generally symmetrical and structured, and can be explained mathematically. These shapes are easy for viewers to
remember and understand because they are what we learned as
children: squares, circles, rectangles, and other simple shapes.
Second, we have Natural Shapes. As the name suggests, these shapes are often found in nature, but not always. Spilled milk creates a natural shape on a table. A green patch of moss on a tree is a natural shape. So is a leaf.
These shapes are often irregular and fluid.
Third, we have the Abstract Shapes, which are simplified versions of natural shapes. The shape on a woman’s restroom door, for example, simplifies the natural shape of a woman wearing a dress so that it can be immediately recognized on a sign. Abstract Shapes are often used for logos and other symbols.