Jumping right in with the form intersections, overall your work here definitely exceeds what we expect to see from students at this stage (we generally expect them to be comfortable with intersections involving only flat surfaces, but to still struggle with those incorporating curving surfaces), but there are still a number of smaller issues that I called out here on your first page.

As a whole you're doing very well, but one of the main points to keep an eye on is that when you think about your intersections, always pay attention to the surfaces that are intersecting themselves. It's easy to guessing based on the kinds of relationships you remember seeing between forms, but this causes us to skip out on actually considering the surfaces that are present, and as I saw in your homework, this can result in cases where you actually end up curving your intersections in the wrong direction. This diagram may help to illustrate what I mean by paying attention to the surfaces - we have to consider the surfaces that are involved, and look at the pairings of surfaces that each contribute to part of the overall intersection line. In that diagram, each of the box's relevant planes (the side and top) engage with a different cross-section of the sphere, giving us curvatures in different directions. The diagram also looks at how a curving surface can be thought of in terms of being like an edge that transitions between two distinct surfaces, but instead of a sudden and momentary shift in surface, it is spread out over a larger space, resulting in a more gradual transition that curves through three dimensions.

We will be looking at this exercise again as part of Lesson 7, but based on what you've done here you're far ahead of what we generally expect, so I'm not worried in any capacity. Just be sure to try and apply what I've explained here and what I've marked out on the work itself, and we'll examine the results when the exercise comes up again.

Continuing onto your object constructions themselves, your work here is fantastic. You've clearly put in an inordinate amount of effort into adhering as closely as possible to the instructions, and as a result, you've worked in a way that prioritizes precision in your constructions, which is very much at the heart of this lesson (and at the heart of lesson 7, which builds further upon these concepts).

Precision is often conflated with accuracy, but they're actually two different things (at least insofar as I use the terms here). Where accuracy speaks to how close you were to executing the mark you intended to, precision actually has nothing to do with putting the mark down on the page. It's about the steps you take beforehand to declare those intentions.

So for example, if we look at the ghosting method, when going through the planning phase of a straight line, we can place a start/end point down. This increases the precision of our drawing, by declaring what we intend to do. From there the mark may miss those points, or it may nail them, it may overshoot, or whatever else - but prior to any of that, we have declared our intent, explaining our thought process, and in so doing, ensuring that we ourselves are acting on that clearly defined intent, rather than just putting marks down and then figuring things out as we go.

In our constructions here, we build up precision primarily through the use of the subdivisions. These allow us to meaningfully study the proportions of our intended object in two dimensions with an orthographic study, then apply those same proportions to the object in three dimensions. Needless to say, your use of subdivision and orthographic plans is extremely thorough and well considered. I'm also pleased to see that you very much avoided the temptation of skipping steps - something we can see with your meticulous use of how the lesson approaches constructing curving structures and surfaces.

Honestly, I don't really see anything that is strictly missing. I do however have one piece of advice, which while it doesn't entirely apply to anything you've drawn here, it crossed my mind after looking at your chair construction and I thought it might be helpful going forward.

Your chair construction features 6 main components - there's the seat, the back, and all four of the legs. While I think the way you approached it here - building it all up in a single bounding box as we would any of the other objects - it's worth taking a moment to talk about cases where we might not approach it all as a single block like this. While the chair is not necessarily such a case, I do think it falls into a grey area.

So what am I talking about? Basically, building it all in a single bounding box gives us a ton of control over the proportions of the overall structure (for example, it allows us to ensure there is a clear and intentional relationship between the height of the chair back and the height of the legs, and the thickness of the seat), it does also come with a lot of extra work involved. More work isn't always necessary, and so we have to consider what the additional labour affords us, and whether it's actually important to our purposes.

An alternative option would be to construct, say, the chair back as its own separate bounding box, and the seat and legs as another. We could separate each leg into its own bounding box as well, but for now we'll just look at having two and consider what we gain and what we lose as a result. Like in our constructions in earlier lessons, this would involve working more inside-out, meaning the proportional relationships as well as the relative orientations of the two bounding boxes would be left up to estimation and approximation. So, if the specific height of the chair back relative to the seat/legs, or its positioning, or angle, do not need to be really specific, approaching it in this way can save us a lot of trouble because the subdivisions for the seat/legs and the subdivisions for the chair back end up isolated from one another. This can free us up to using more subdivision to lay out the various rods that make up the chair back without having that spill over into complicating the seat/legs.

Where I think this would be a more clearly preferable choice over building everything in a single bounding box is when the different components aren't always set at the same angle to one another. For example, a pair of glasses - many students will try to construct them all in one bounding box, resulting in a lot of complexity for what are otherwise fairly simple arms (or "temples" as I believe they're actually called). Instead, constructing each temple/arm in its own bounding box would help us avoid drawing the glasses overly stiffly (having a pair of glasses drawn with the arms completely open might appear a little odd and unnatural), while also saving us some extra hassle.

Basically anything separated from the main body of an object with a hinge might be a good candidate for being placed in its own separate bounding box, and having its relationship to the core estimated, instead of all crammed into the same bounding box.

Anyway! I rambled on for a good bit on what was ultimately a minor point, but as a whole your work is really, really well done. I'll go ahead and mark this lesson as complete. Keep up the great work.