The document discusses different methods for developing the surfaces of solids onto a plane. There are four main types of development - parallel-line, radial-line, triangulation, and approximate. Parallel-line development is used for prisms and cylinders, radial-line development is used for pyramids and cones, and triangulation development divides surfaces into triangles for transition pieces. The approximate method is used for objects with double curved or warped surfaces like spheres.