Question

When billy flips a coin, it appears to be different shapes as it rotates in the air. sometimes it looks like a circle, sometimes more oval, and, when flat, like a thin sliver. by using which perceptual rule does billy know that although his perception of the penny's shape may change, it never actually changes shape?

Answer 1

The answer to this question is Constancy.
Perceptual rule of constancy is an object or quality as constant even though our sensation of the object change.
When the coin is tossed in the are, the movement created a visual illusion that make the coin look like it transforms into several different shapes, but it actually stay in the exact same shape.