Ellipses

Math

Definition

An ellipse is an oval-shaped conic section defined as the set of all points where the sum of distances to two fixed points (foci) is constant. It has a major axis (longest diameter) and a minor axis (shortest diameter).

Examples

  • Earth's orbit around the Sun is an ellipse with the Sun at one focus
  • A whispering gallery uses the reflective property of ellipses
  • Satellites often follow elliptical orbits
Key Fact

Standard form: (x-h)²/a² + (y-k)²/b² = 1; c² = a² - b² (where c = distance from center to focus)

Study This Concept

Practice ellipses with free review games in these units: