The word (plural ellipses) originates from the Ancient Greek: , lleipsis meaning 'leave out'. The elongation of an ellipse is measured by its eccentricity $${\displaystyle e}$$, a number ranging from $${\displaystyle e=0}$$ (the limiting case of a circle) to $${\displaystyle e=1}$$ (the limiting case of infinite elongation, no longer an ellipse but a parabola). Typical equation: (, a closed conic section shaped like a flattened circle and formed by an inclined plane that does not cut the base of the cone. An eclipse occurs when the sun is blocked by the Moon or the Earth. It has two focal points. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Standard equation. If the foci are identical with each other, the ellipse is a circle; if the two foci are distinct from each other, the ellipse looks like a squashed or elongated circle. In most definitions of the conic sections, the circle is defined as a special case of the ellipse, when the plane is parallel to the base of the cone. NASAs 1970s Viking Mars missions had an estimated landing ellipse of 280x100km. The general equation of an ellipse centered at (h,k)(h,k)is: (xh)2a2+(yk)2b2=1(xh)2a2+(yk)2b2=1 when the major axis of the ellipse is horizontal. These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ellipse.' Delivered to your inbox! On Dec. 18, a triumphant Johnson appeared on the Ellipse outside the White House to light the national Christmas tree. The eccentricity of an ellipse is a measure of how stretched out it is. When does an ellipse occur? a plane curve such that the sums of the distances of each point in its periphery from two fixed points, the foci, are equal. See the full definition for ellipse in the English Language Learners Dictionary, Thesaurus: All synonyms and antonyms for ellipse, Nglish: Translation of ellipse for Spanish Speakers, Britannica.com: Encyclopedia article about ellipse. Ellipse Definition: On a plane, ellipse is defined as follows - If two special points (called the foci) are picked on a plane and if we collect all the points around those foci such that the sum of the distances between any point in that collection and the two foci are a constant, then the locus of all these points form a curve called Ellipse.. The midpoint between the foci is the center. which use the trigonometric functions sine and cosine.. An ellipse is a figure bounded by a continuous curve, whose nature will be shown presently. Updated with more commonly confused words! That spread, Rothermel found, drove outward in a thin, expanding edge along an ellipse. The New Dictionary of Cultural Literacy, Third Edition Put two pins in a board, put a loop of string around them, and insert a pencil into the loop. Find 58 ways to say ellipse, along with antonyms, related words, and example sentences at Thesaurus.com, the world's most trusted free thesaurus. Published by Houghton Mifflin Harcourt Publishing Company. Definition and Terminology: Ellipse is also defined as the locus of a point which moves such that the sum of its distances from the two fixed points is a constant which is equal to the length of the major axis. Ellipse is a closed, symmetric curve shaped like an oval, which can be formed by intersecting a cone with a plane that is not parallel or perpendicular to the cone's base. Send us feedback. In mathematics, an ellipse is a plane algebraic curve where the sum of the distances from any point on the curve to two fixed points is constant. Therefore, from this definition the equation of the ellipse is: r 1 + r 2 = 2a, where a = semi-major axis. Can you spell these 10 commonly misspelled words? The American Heritage Science Dictionary An oval may or may not fit the definition of an ellipse. With these advances, the Perseverance landing, Now, Inoue will head back to the lab and look at the, Pedestrian gates would be placed to allow access to Pennsylvania Avenue and enclosed park areas including the, At some point in that heads-down work, the organizers will task the teams with writing code that can take control of the actual on-orbit satellite, which will be carving an, The storm will move into the right entrance region of the jet streak, shown by the large red, Kepler himself later rejected this model, after concluding that the orbits of the planets did not form the singular perfect shape of a circle, but instead had the ugly appearance of an, In other words, the orbit can be elliptical, but the, Post the Definition of ellipse to Facebook, Share the Definition of ellipse on Twitter. The disk was an impossibly long ellipse now, surrounded by a vast array of smaller bodies, fragments and contents of the ship. The other three are the circle, the hyperbola, and the parabola. Published by Houghton Mifflin Harcourt Publishing Company. As a result, in an elliptical room, a person whispering at one focus is easily heard by someone at the other. The ellipsis , . Dictionary.com Unabridged A closed, symmetric curve shaped like an oval, which can be formed by intersecting a cone with a plane that is not parallel or perpendicular to the cone's base. A member of the class of curves that are intersections of a plane with a cone of revolution. Based on the Random House Unabridged Dictionary, Random House, Inc. 2021, Collins English Dictionary - Complete & Unabridged 2012 Digital Edition All rights reserved.