Cylindrical coordinates locate a point [math]P[/math] in space by an ordered triple [math]\left(r,\theta,z\right)[/math] in which [math]r\ge0[/math].[br][list][*][math]r[/math] and [math]\theta[/math] are polar coordinates for the vertical projection of [math]P[/math] on the [math]xy[/math]-plane.[/*][*][math]z[/math] is the rectangular vertical coordinate.[/*][/list]By setting ranges for [math]r[/math], [math]\theta[/math], and [math]z[/math], we can describe certain solid objects in space. Use this interactive figure to get a feel for the types of solids that can be described by using cylindrical coordinates.