Parabola the limit of the Ellipse when one Focus passes to infinity
Intercept on Axis by two Lines, equal to projection of distance between their
Poles
Locus of foot of Perpendicular from Focus on Tangent
Locus of intersection of Tangents which cut at right Angles (see also pp. 285, 352) 205
Angle between two Tangents half that between corresponding Focal Radii
Circle circumscribing Triangle formed by three Tangents passes through Focus
(see also pp. 214, 274, 285, 320)