# Cone (geometry): Quiz

Question 1: The ________ of a right circular cone is the maximum angle between two generatrix lines; if the generatrix makes an angle θ to the axis, the aperture is 2θ.
Focal lengthAperturePhotographyF-number

Question 2: For example, a pyramid is technically a cone with a ________ base.
PolygonRegular polytopePolyhedronPolytope

Question 3: The boundary of an infinite or doubly infinite cone is a conical surface, and the intersection of a plane with this surface is a ________.
EllipseConic sectionHyperbolaParabola

Question 4: In common usage in elementary geometry, however, cones are assumed to be right circular, where right means that the axis passes through the centre of the base (suitably defined) at right angles to its plane, and circular means that the base is a ________.
Polar coordinate systemConic sectionCirclePi

Question 5: The ________ of a conic solid of uniform density lies one-quarter of the way from the center of mass of the base to the vertex, on the straight line joining the two.
Center of massTireVehicle dynamicsCar handling

Question 6: The axis of a cone is the straight line (if any), passing through the apex, about which the lateral surface has a ________.
IcosahedronDihedral groupSymmetry groupRotational symmetry

Question 7: (For the connection between this sense of the term "directrix" and the directrix of a ________, see Dandelin spheres.)
EllipseHyperbolaConic sectionParabola