We prove in this paper some integral formulas about volume and surface area which are the extensions of the classical formulas such as Guldin-Pappus’s theorem about the solid of rotation and the surface of rotation and Holditch’s theorem about the area of the domains bounded by the loci of three points on a segment that moves on the euclidean plane. The formulas we prove are so elementary that they may be found in some literature, but the proofs here given are very simple by the use of moving frames and I assume that they are of some interest.