Referring to ching book in this section ching is talking and describing about all the different kinds of structure (structural spans, structural  patterns) and what is it made or formed of (planks or decking, joists, beams or griders, slab or plate structure, bearing wall and column/ beam frame). He’s also mentioned te different types of bracing depending on the perpose of the building and the meterial that it is made of ( knee bracing, k- brace, cross bracing, and cable bracing). He also taked about structular grides that some parts of the grides can be removed or even sometime it would be shifted at an angle  to the side of the grid.