Mr. Carpenter, Mr. Fisherman, Mr. Smith and Mr. Taylor live some
distance from each other, and if you look at a map, you see their
houses are in the corners of a square (points A, B, C and D in the
picture). They want to build a road network between their houses so
that they can conveniently visit each other.
However, these men are frugal, and they want to build as few miles of road as possible. What should their road network look like, so that it would be possible to travel from each house to the others, but the total length of the roads is minimized?
Published in Njet Problem! collection 2001-08-31.