Two nappes of a right circular cone meet at a point called the vertex.
It is the vertex. It can also be called the apex but that has a connotation of being the top-most point and so is not appropriate when both nappes are concerned.
It will be a hyperbola.
An Ellipse
hyperbola
ellipse
It is the vertex. It can also be called the apex but that has a connotation of being the top-most point and so is not appropriate when both nappes are concerned.
The intersection forms a hyperbola.
A hyperbola
edge-Apex
if a right circular cone intersects a plane that goes through both nappes of the cone, but not through the vertex, the resulting curve will be a hyperbola
Hyperbola
A hyperbola.
It will be a hyperbola.
A right circular cone looks like a martini glass. Actually, the martini glass is only a part of one half of the cone. Think also of an ice cream cone, again being part of one half. Formally, the right circular cone is the surface in three-dimensional space swept by a line that intersects a point and the domain of the circumference of a circle, said point lying on a line perpendicular (right angle) to the circle and intersecting its radius. Since the line sweeps through a point, there are two nappes, one on each side of that single point. The perpendicular line is called the axis, and the point is called the vertex.
An Ellipse
Then the intersection is a hyperbola.
hyperbola