Final answer:
A person lying on their stomach with arms at their sides is in the prone position, which is used for certain examinations and surgeries.
Step-by-step explanation:
A resident who is lying on her stomach with her arms at her sides is in a prone position. This definition applies when a body is lying face down, as opposed to the supine position, where the body would be lying face up. The prone position is often referenced in medical and healthcare settings, particularly when examining the back or during certain surgical procedures. Other options, such as the lateral position refers to lying on one's side, and the Fowler's position is when the patient is seated in a semi-upright position, typically at a 45 to 60-degree angle.