Fencing Sheep
An engineer, a physicist, and a mathematician are shown a pasture with a herd
of sheep, and told to put them inside the smallest possible amount of fence.

The engineer is first. He herds the sheep into a circle and then puts the
fence around them, declaring, "A circle will use the least fence for a given
area, so this is the best solution."

The physicist is next. She creates a circular fence of infinite radius around
the sheep, and then draws the fence tight around the herd, declaring, "This
will give the smallest circular fence around the herd."

The mathematician is last. After giving the problem a little thought, he puts
a small fence around himself and then declares, "I define myself to be on the