A perfect circle is a two-dimensional shape where all points on the boundary are equidistant from a central point, known as the center. This distance is called the radius. In mathematics, a perfect circle is defined by the equation x^2 + y^2 = r^2, where r represents the radius. Perfect circles are commonly found in nature and human-made objects, such as wheels, coins, and bubbles. They are significant in various fields, including geometry, art, and engineering, due to their unique properties and symmetry, which make them aesthetically pleasing and structurally efficient.