1. The problem statement, all variables and given/known data In spherical polar coordinates, the infinitesimal displacement ds is given by: [tex] ds^2 = dr^2 + r^2 d\theta ^2 + r^2 \sin \left( \theta \right)^2 d\phi ^2 [/tex] Can I find the volume of a sphere using ds? 3. The attempt at a solution I know the spherical volume-element is given by [tex]dV = r^2 \sin \left( \theta \right)drd\theta d\phi[/tex]. I can always make a figure showing the geometry of spherical coordinates, but is there a general way of finding the volume from ds? Perhaps finding the area, and then the volume?