What is a tangram? It is more easily seen and understood than defined in words. But to put it briefly, it is a geometric dissection puzzle in which seven standard pieces (five triangles, one square, one rhomboid) are used to make images of various objects. The origin of the name is not known, but the game itself is of Chinese origin, and for centuries it has been one of the most popular diversions in the Orient. The tangram is not entirely new to...