Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. In mathematics, a lituus is a spiral in which the angle is inversely proportional to the square of the radius (as expressed in polar coordinates). In mathematics, a spiral is a curve which emanates from a central point, getting progressively farther away as it revolves around the point.A "spiral" and a "helix" are both technically spirals even though they each represent a different object.