>> In this section, we'll be talking about a family of geometric figures called conic sections and they are so named because of their relationship to the cone: cone, conic. That's that relationship. Now the way that they emerge is by taking a cone and its reflection and looking at the cross section of this figure with a plane. Now you can see some figures drawn in your textbook that illustrate the situation very well, but imagine a plane just cutting through the cone like this. Then what we would have is we would have a circle. And if the plane were kind of twisted a little bit like this, then the figure would end up being an ellipse. Now the figures that are in this group of - this family of - geometric figures, these conic sections or simply conics, are the circle, parabola, ellipse and hyperbola.