The emitter is located on the curve determined by the two intersecting hyperboloids. The receiver is located at the point where three hyperboloids intersect. "Hyperboloids" of different power capability differ in their effect. The curvature lines are sections with one (blue) and two (purple) sheeted hyperboloids. These include ellipsoids, cylinders, cones, paraboloids, and hyperboloids in all of their various forms. The curvature lines are intersections with ellipsoids (blue) and hyperboloids of two sheets (purple). Quadric surfaces include ellipsoids (including the sphere), paraboloids, hyperboloids, cylinders, cones, and planes. Imaginary hyperboloids are frequently found in mathematics of higher dimensions. The "bishop's mitre" spires are capped with hyperboloids. In an ideal Penning trap the ring and endcaps are hyperboloids of revolution. These forms, based on non-Euclidean hyperbolic geometry, are known today as hyperboloids of revolution. One-sheeted hyperboloids are used in construction, with the structures called hyperboloid structures.