The model shows a cone of revolution and a section plane E that forms the same angle with the axis of revolution; it forms the cone's generator. Consequently, E intersects the cone of revolution along a parbola. Furthermore, the model shows the great circle of the Dandelin sphere, which contains the cone's axis of revolution and the focus of the parabola. The line segments required to derive the focus and directrix properties of the parabola are included in the model.