National Protective Security Officer Training Program Practice Test

The shape of a person's face is primarily determined by the jawline, which serves as a fundamental structural feature that delineates the overall contour of the face. The jawline provides the framework for how the face is perceived from various angles, thereby playing a significant role in defining whether a face is considered round, square, oval, or heart-shaped.

While other facial features, such as the forehead or cheeks, contribute to the face's appearance and can influence its perception, they do not fundamentally dictate its shape to the same extent as the jawline. The jawline effectively outlines the bottom half of the face, establishing the balance and proportions that are crucial in determining the overall facial shape. Thus, its shape and prominence can cause substantial variations in how a face is categorized in terms of its overall form.