In this reading  ching summarizes different connections with wood, steal and concrete. He also talks about arches.  There are different kind of arches Gothic, lancet and drop arches which can be used in different occasions. There are different parts to these arch such and the crown, spring extrados , intrados, and arch axis. There are also lintels which can support with load when using a span. These lintels are steal angle, reinforced bricks, concrete masonry , and precast concrete. ching explains how joist are spaced 12″,16″, 24″ depending on the load they also have cavities which is for pipping and wiring. these joist have different spanning ranges depending on the size of the joist. they should never exceed 1/360th of span. There are also beams for wood. there are box beam flinch beam and spaced beam. There are wood sub flooring, decking , and wood planks. There are also Steal beam.  There are S shape, W shape , C shape,  and Structural tubing. Rule of thumb  for depth beams span 20 and girder span 15  and the with has to be 1/3 to 1/2 of the depth.