The left family share vertexes, the right are confocal. History Description Formulas Properties Related Web Sites History See the History section of Conic Sections page . Description Ellipse describe a family of curves. Together with hyperbola and parabola , they make up the conic sections . Ellipse is also a special case of hypotrochoid .
Eccentricity is a number that describe the degree of roundness of the ellipse.
The smaller the eccentricy, the rounder the ellipse. The distance between the vertexes are called major axis or focal axis. A line passing the center and perpendicular to the major axis is the minor axis. Properties Ellipse as Hypotrochoid Ellipse can be generated as a hypotrochoid . This is easily solved with the above information.