Construction of a Conic
Diagram showing how to construct a conic when given the focus and the auxiliary circle. If the focus is outside the circle, we get a hyperbola. If it’s inside the circle, we get an ellipse. If the auxiliary circle is a straight line (radius is infinite), we get a parabola.
Keywordscone, ellipse, ellipses, circle, conic section, hyperbola, construction, circles, focus, conics, foci, construct, hyperbolas
Arthur Latham Baker The Elements of Solid Geometr with Numerous Exercises (Boston, MA: Ginn & Company, 1893)