we think of a cone like an ice cream cone, or a funnel. In mathematics, a cone is typically referring to the figure in this geogebra. Sometimes called a double cone, but is simply the shape you get when you take a line through the origin and rotate it around an axis. They are made up of the top nappe, and the bottom nappe. when cut by a plane, the plane sometimes only hit one nappe, sometimes you stop hitting the nappe, sometimes you hit both. how would you categorize these?