A circle is a geometric shape defined as the set of all points in a plane that are equidistant from a fixed point, known as the center. The distance from the center to any point on the circle is called the radius, while the distance across the circle through the center is known as the diameter, which is twice the length of the radius. Circles are characterized by their perfect symmetry and lack of corners or edges, making them a fundamental concept in mathematics and a frequent occurrence in nature and design. The circumference, or the perimeter of the circle, is calculated using the formula 𝐶=2𝜋𝑟C=2πr, where 𝑟r represents the radius and 𝜋π (pi) is a constant approximately equal to 3.14159. Circles are essential in theoretical mathematics and have practical applications in various fields, such as engineering, architecture, and art, where their properties of balance and harmony are often utilized.