What phenomenon explains why we perceive objects as having a constant shape despite changes in the angle from which we view them?

The phenomenon that describes our ability to perceive objects as having a constant shape, regardless of the angle from which they are viewed, is known as shape constancy. This perceptual stability allows us to recognize that an object remains the same shape even when our perspective changes, such as when we look at a door from different angles. Our brain processes the visual information and adjusts for changes in perspective, leading us to maintain a consistent perception of the object's shape.

The other options are relevant to visual perception but do not specifically address the constancy of shape. Size constancy pertains to our ability to perceive an object as the same size despite variations in distance, which affects how large it appears on the retina. Figure-ground perception deals with distinguishing an object from its background, while depth perception allows us to interpret the distance of objects in a three-dimensional space. None of these concepts directly relate to maintaining a consistent perception of shape across varying viewpoints, which is why shape constancy is the correct choice.