Final answer:
Pyramids, with their precise and regular attributes, are classified as geometric forms, a term used in the arts to describe three-dimensional shapes or the illusion of it.
Step-by-step explanation:
Forms such as pyramids, which tend to be precise and regular, are known as geometric forms. In the context of art, form refers to an actual, three-dimensional shape or the illusion of three-dimensionality. Form can be either geometric, characterized by precise, mathematical shapes and planes, or organic, denoting irregular and natural forms. The shapes of Cubism, for example, demonstrate a reconstruction of subjects into geometric shapes or geometric abstraction to bring a three-dimensional perspective to the viewer.