What term describes irregular geometric shapes that are subdivided into smaller copies of the whole?

The correct term for irregular geometric shapes that are subdivided into smaller copies of the whole is "fractal type patterns." Fractals are intricate structures where each smaller section mirrors the overall shape, creating a repeating pattern at different scales. This characteristic allows for the formation of complex shapes from simple rules, exemplified in nature through phenomena like snowflakes, coastlines, and fern leaves.

In comparison, symmetrical patterns emphasize uniformity and balance, with identical halves, rather than the recursive nature of fractals. Geometric sequences focus on numerical patterns rather than shapes or designs, and harmonious designs refer to aesthetically pleasing arrangements without the inherent self-similar quality that defines fractal patterns. Thus, recognizing the unique properties of fractals is key to understanding why they are the correct answer in this context.