Final answer:
The object, SID, and image receptor are the three elements that affect shape distortion in imaging.
Step-by-step explanation:
The three elements that affect shape distortion are the object, the SID (source-to-image distance), and the image receptor. These elements play a role in determining the size, clarity, and distortion of the image formed.
The object refers to the object being imaged or observed, and its characteristics can affect the shape of the image produced. The SID is the distance between the X-ray source and the image receptor, and it impacts image magnification and distortion. The image receptor is the medium that captures the image, and it determines the quality and accuracy of the final image produced.