Explore Ellipse on MathWorld

A conic section with eccentricity less than one. It resembles a squashed circle.

Ellipse is a high school-level concept that would be first encountered in a pre-calculus course covering conic sections. It is listed in the California State Standards for Algebra II.


Circle: A circle is the set of points in a plane that are equidistant from a given center point.


Conic Section: The conic sections are the classes of nondegenerate curves generated by the intersections of a plane with one or two nappes of a cone. A conic section can also be realized as the zero set of a quadratic equation in two variables.

Classroom Articles on Conic Sections

  • Hyperbola
  • Parabola
  • Locus

  • Classroom Articles on Pre-Calculus (Up to High School Level)

  • Asymptote
  • Natural Logarithm
  • Complex Conjugate
  • Normal Vector
  • Complex Number
  • Parametric Equations
  • Complex Plane
  • Plane
  • Cross Product
  • Plane Curve
  • Curve
  • Polar Coordinates
  • Determinant
  • Range
  • Domain
  • Rational Function
  • Dot Product
  • Reflection
  • e
  • Rotation
  • Exponential Function
  • Rotation Matrix
  • Function
  • Scalar
  • i
  • Spherical Coordinates
  • Imaginary Number
  • Tangent Line
  • Inverse Function
  • Translation
  • Logarithm
  • Vector