ABSTRACT
T his appendix presents the geodesic math necessary to subdivide the principle poly-hedral triangle (PPT) or the least common denominator triangle (LCD) based on Class I, II, and III schemas presented earlier in this book. With the algorithms shown here, you can derive the coordinates of grid points, arc, and chord distances between them and all edge and face angles. Math techniques are described for each of the classes. In addition, this appendix includes some handy algorithms to solve common 3D geometric problems, such as finding the perpendicular to a plane, or the shortest distance between two nonintersecting lines in three dimensions.
