5.4.1 Geometric description of conic section

. . Geometric description of conic section A plane perpendicular to the axis of the cone (plane C ) intersecting any one nape of the double napped cone yields a circle (Fig. . ) . The plane E , tilted so that it is not perpendicular to the axis, intersecting any one nape of the double napped cone yields an ellipse (Fig. . ). When the plane is parallel to a side of one napes of the double napped cone, the plane intersecting the cone yields a parabola (Fig. . ). When the plane is parallel to the plane containing the axis of the double cone, intersecting the double cone yields a hyperbola (Fig. . ). Fig. . Fig. . Fig. . - -