Definitions of ellipse terms
- diameter
- Any line segment through the center of the ellipse with endpoints on the ellipse.
- major axis
- The line segment containing the foci whose endpoints are on the ellipse. Alternatively, the longest diameter of the ellipse.
- minor axis
- The shortest diameter of the ellipse that passes through the center. Alternatively, the line segment perpendicular to the major axis and through the center with endpoints on the ellipse.
- semimajor axis
- A piece of the major axis that has one endpoint at the center and the other on the ellipse.
- semiminor axis
- A piece of the minor axis that has one endpoint at the center and the other on the ellipse.
- vertex
- An endpoint of the major or minor axis.
- vertices ("VER-ti-sees")
- Plural of vertex.
