The face on the ride "It's a small world" at Disneyland smiles not only because it wants everyone to be happy, but because it knows it is a circle. All points around the center of the face are equal distance, therefore making it a circle.
Optical Illusions
Optical Illusions trick people into seeing things that aren't really there or aren't really happening. They can be all shapes and sizes. Circles are very common in optical Illusions. For example, the picture on the lower right shows two circles, with alternating colors. To the people who view this illusion, it looks like the circles are moving. However, in reality, they are staying still.
Please reload
A Circle is the set of all points that are a fixed distance from a fixed point.
