The author happened upon the formulas for area presented in this paper when working on an ergodic problem proposed to him by Professor B. H. Neumann. A,search of the literature reveals that the planar case implies Guldin's Formula and is practically equivalent to it. However, as far as we have been able to determine, the particular viewpoint we have chosen is either unknown or is little known to mathematicians in this country. Briefly put, we shall develop a formula which makes possible the corni position of curves in the polar coordinate plane and we shall give an area-preserving mapping of a developable surface onto the polar plane which is not the customary isometric mapping. There seems no good reason that the planar case should not be presented in elementary calculus since a proof can be given on that level. We shall, however, give a proof which holds for two or three (actually n) dimensions.