The vesica piscis is a symbol made from two circles of the same radius, intersecting in such a way that the center of each circle lies on the circumference of the other. The name literally means the bladder of the fish in Latin. The shape is also called mandorla ("almond" in Italian ).It is also known in the early Mesopotamian, African, and Asian civilizations.It has been the subject of mystical speculation at several periods of history, perhaps first among the Pythagoreans, who considered it a holy figure. The mathematical ratio of its width (measured to the endpoints of the "body", not including the "tail") to its height was reportedly believed by them to be 265:153. This ratio, equal to 1.73203, was thought of as a holy number, called the measure of the fish. (Wikipedia)