If we imagine a plane which passes through the rotation axis, that surface "cuts" two slits with an hyperbolic shape on the plane.

If in the previous problem, we have a rod passing through the axis of rotation, a cone is obtained and, of course, if we have a rod parallel to the axis of rotation, we obtain a cylinder.

The following application allows the different forms to be obtained, by giving the user the possibility of changing both the distance and the tilt of the rod in relation to the rotation axis.

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