Which of the following represents the main types of hair shapes?

The main types of hair shapes are indeed represented by straight, wavy, curly, and coily. These classifications describe the overall pattern and structure of the hair strands.

Straight hair has no curl pattern and lies flat. Wavy hair features a slight wave and body without forming tight curls, giving it a more textured appearance. Curly hair forms distinct curls or spirals, which can vary in tightness and volume. Coily hair includes very tight curls or kinks that are often densely packed together, giving it a unique texture and shape.

This classification is fundamental in cosmetology as it affects the types of hair care products used, as well as styling techniques. Understanding these core hair shapes allows cosmetologists to better meet the needs of their clients based on their specific hair type and texture.