The basic technique for creating objects is constructing a set of faces. A face is planar meaning that it is formed from a sequence of vertices residing in a plane. Different faces may reside in different, non-parallel planes. In fact, this must be true inorder to create a 3-dimensional object.
We investigate in this tutorial the creation of faces and, more generally, the creation of 2-dimensional geometry from a sequence of vertices such as a polygon. We will be working in the x-y coordinate plane, in which case the z-coordinate is zero. Note that moving the geometry outside of the x-y coordinate plane requires only a change in the z-coordinates.