Ladders, Envelopes, and p-Norms

References and Additional Information

Solving the Ladder Problem on the Back of an Envelope.
Mathematics Magazine
, Volume 80, Number 3, June 2007, pp 163 - 182.
Doug Ensley's Family of Curves and Envelope Applet
Combined Ellipse and Line Applet for Astroid
Uncommon Mathematical Excursions: Polynomia and Related Realms