# Conic-section sentence example

It is therefore a

**conic section**having its eccentricity equal to unity.If the attraction of a central body is not the only force acting on the moving body, the orbit will deviate from the form of a

**conic section**in a degree depending on the amount of the extraneous force; and the curve described may not be a re-entering curve at all, but one winding around so as to form an indefinite succession of spires.If the roof be not horizontal, we may obtain in this way any form of

**conic section**.The relation of the ellipse to the other conic sections is treated in the articles

**Conic Section**and Geometry; in this article a summary of the properties of the curve will be given.In projective geometry it is convenient to define a

**conic section**as the projection of a circle.AdvertisementIn Newton's method, two angles of constant magnitude are caused to revolve about their vertices which are fixed in position, in such a manner that the intersection of two limbs moves along a fixed straight line; then the two remaining limbs envelop a conic. Maclaurin's method, published in his Geometria organica (1719), is based on the proposition that the locus of the vertex of a triangle, the sides of which pass through three fixed points, and the base angles move along two fixed lines, is a

**conic section**.If the law of attraction is that of gravitation, the orbit is a

**conic section**- ellipse, parabola or hyperbola - having the centre of attraction in one of its foci; and the motion takes place in accordance with Kepler's laws (see Astronomy).