Let the endpoints of a line segment slide along two perpendicular axes.
[i]What is the envelope of the segment?[/i]
This is problem #52 in Heinrich Dörrie's [i]100 Great Problems of Elementary Mathematics[/i]
Solution inspired by Noel Lambert's collection of Curves:
[url]http://www.geogebratube.org/collection/show/id/3217[/url]
