Contours on a surface

This cone is part of a lesson for a multivariable calculus class in which students learn how to make sense of a function whose domain is a surface in three dimensions. The cone is meant to model the surface defined in cylindrical coordinates by the equation *z*=*r*. This page is meant to complement the paper "3D Printed Manipulatives in a Multivariable Calculus Classroom" which will appear in PRIMUS.