Lindelöf's Catenary Theorem
The surface of revolution generated by the external catenary between a fixed point a and its conjugate on the envelope of the catenary through the fixed point is equal in area to the surface of revolution generated by its two Lindelof tangents which cross the axis of rotation at the point a and are calculable from the positions of the points and catenary.
See also
Catenary, Envelope, Lindelöf's Theorem, Surface of RevolutionExplore with Wolfram|Alpha
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Cite this as:
Weisstein, Eric W. "Lindelöf's Catenary Theorem." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/LindelofsCatenaryTheorem.html