An ellipse is a figure in geometry ranking next in importance to the circle, and produced when any cone is cut by a plane which passes through it not parallel to nor cutting the base. Kepler discovered that the paths described by the planets in their revolutions round the sun are ellipses, the sun being placed in one of the foci. To describe an ellipse: At a given distance"on the surface on which the ellipse is to be described fix two pins, and pass a looped string round them. Keep the string stretched by a pencil, and move the pencil round, keeping the string at the same tension, then the ellipse will be described. A line drawn from any point in the curve perpendicularly to the axis is an ordinate to the axis. Any straight line drawn through the centre and terminated both ways by the curve is called a diameter. Research Ellipse
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Abbreviations
SciTech
Research Ellipse
