Promised only as much land as an ox-hide could enclose, a queen found the loophole
According to legend, the Phoenician princess Dido fled to North Africa and asked a local king for land to settle. He mockingly agreed to give her only as much ground as a single ox-hide could cover. Given a knife and one ox-hide, how could she possibly enclose enough land to found an entire city?
Reveal the answer
She cut the hide into one continuous, extremely thin strip, long enough to encircle a huge area of coastline, and used the shoreline itself as one side of the boundary to enclose even more ground with the same length of strip. The city she founded became Carthage. Mathematicians now call the underlying question, what shape encloses the most area for a given boundary length, the isoperimetric problem, and the answer is always a circle, or a semicircle against a straight edge.
— Virgil, Aeneid — 1st century BC; mathematical formulation as the isoperimetric inequality