A circle is a fundamental two-dimensional shape defined as all points at a given distance from a fixed point in a plane. Here's a breakdown of its key aspects: Shape: It's a closed, curved figure with no corners or edges. Center: The fixed point mentioned earlier is called the center of the circle. Radius: The distance between the center and any point on the circle's edge is called the radius. All points on the circle are the same distance away from the center. Diameter: The diameter is the straight line passing through the center that intersects the circle's edge at two opposite points. It's essentially twice the length of the radius (diameter = 2 * radius). Here are some additional properties of circles: Circumference: This is the total length of the circle's boundary. It can be calculated using the formula: circumference = 2πr (where π is a mathematical constant roughly equal to 3.14 and r is the radius). Area: The enclosed area within the circle is calculated using the formula: area = πr². Symmetry: Circles have both rotational symmetry (can be rotated around the centre and look identical) and reflectional symmetry (can be folded in half across any diameter and the two halves will match). Circles are incredibly important shapes in various fields, including geometry, physics, engineering, and even everyday objects.