What is the Difference Between Circle and Ellipse?

The main difference between a circle and an ellipse lies in the distance of their points from two fixed points called foci.

• Circle: A circle is a locus of all points on a plane that are equidistant from a single point called its center. All points on the circle are equally far from the center of the circle. The radius of a circle is the same for all points.
• Ellipse: An ellipse is the set of all points in a plane where the sum of the distances to two fixed points, called foci, is constant. The points on an ellipse are not equally distant from the center. Instead, the sum of the distances from two foci is constant. An ellipse can vary in shape from broad and flat to almost circular, depending on the distance between the foci. The major axis is the longest segment across the ellipse and connects the two vertices, while the minor axis is the shortest segment across the ellipse and connects the two covertices.

In summary, a circle is a special case of an ellipse where both foci are at the center, and all points on the circle are equally distant from the center. An ellipse, on the other hand, has points that are not equally distant from the center, and the sum of the distances from two foci is constant.

Comparative Table: Circle vs Ellipse

Here is a table comparing the differences between a circle and an ellipse:

() A circle is a special form of an ellipse where both foci are at the center. (*) An ellipse has two fixed points called foci.

• A circle is a special type of ellipse with a constant radius and a round shape.
• An ellipse has a varying radius and its shape can vary from being broad to flat to nearly circular.
• Circles and ellipses are both conic sections formed when a plane intersects a cone.