A conic is the intersection of a plane and a right circular cone. The four basic types of conics are parabolas, ellipses, circles, and hyperbolas. This document discusses the concept of circles. A circle is a set of all points in a plane that are a fixed distance, called the radius, and from a point called its center. Equation of a circle: The distance formula can be used to find the equation of a circle. Let the center of the circle be represented by the ordered pair (h, k) and the radius of