In psychology, the basic shapes are circle, square, and triangle. Star is not a basic shape.

The Gestalt principle of closure states that we tend to perceive objects as wholes rather than as individual parts.

Shape constancy is not an optical illusion. It is a perceptual phenomenon that allows us to perceive objects as having the same shape regardless of their orientation or distance from us.

Contextual illusion is the phenomenon that occurs when we perceive an object as being larger or smaller than it actually is due to its context.

Culture is not a factor that influences shape perception.

Orientation illusion is the phenomenon that occurs when we perceive a shape as being different from what it actually is due to its orientation.

Categorization task is not a type of shape discrimination task.

Symmetry illusion is the phenomenon that occurs when we perceive a shape as being more regular or symmetrical than it actually is.

Object recognition task is not a type of shape completion task.

Complexity illusion is the phenomenon that occurs when we perceive a shape as being more complex or detailed than it actually is.

Lighting is not a factor that influences shape constancy.

Convexity illusion is the phenomenon that occurs when we perceive a shape as being more convex or concave than it actually is.

Go/no-go task is not a type of shape matching task.

Elongation illusion is the phenomenon that occurs when we perceive a shape as being more elongated or stretched than it actually is.

Categorization task is not a type of shape rotation task.