Which cue involves knowing the size of objects for depth perception?

The cue that involves knowing the size of objects for depth perception is accurately identified as the known size of objects. This concept is rooted in our understanding that familiar objects have a predictable scale. When we recognize an object whose dimensions we are already aware of, such as a car or a human figure, we can use this information to judge how far away the object is.

For example, if you see a figure that appears to be the size of a standard car, it is likely closer to you than one that appears to be the size of a toy model. This ability to interpret the perceived size of familiar objects is crucial in various aviation scenarios, where depth perception can significantly influence spatial awareness and decision-making.

In contrast, linear perspective focuses on how parallel lines seem to converge at a distance, while fading shades of colors relate to how colors appear softer and lighter as they recede into the distance. Terrestrial association pertains to how we understand objects based on their context within the environment. These cues assist with depth perception but do not specifically rely on the known size of objects like the chosen correct answer does.