Starting with your form intersections, you're making good progress here, but there is still room for further improvement. That's pretty standard - we introduce the form intersections in Lesson 2 before we actually really start developing students' spatial reasoning skills (which we do through the constructional drawing exercises in lessons 3-5), so this point serves as a good opportunity to look at where students are at with this highly diagnostic exercise, and provide additional advice/explanation to keep them on the right path. It's pretty normal for students to be fairly comfortable with intersections involving flat surfaces, but to still have a tough time with those involving rounded structures. That's not too far off from where you are, just a little different - you're more comfortable with curving surfaces than most at this stage (although still running into some issues), but you're also running into some issues with flat surfaces. On average though, you're progressing well.

There are a few things I want to suggest, but first here's some notes directly on your work. Here are the main things to keep in mind:

• It's best not to draw "through" your intersections as we do for our forms. With drawing the forms it helps provide us with more information on how they all sit in 3D space, but when doing so with the intersections it honestly makes it more likely that we're going to confuse ourselves, which actually reduces the effectiveness of the exercise. Sticking to the parts of the intersection line that you can actually see will help you focus more on the problem at hand.

• Keep in mind that intersections occur between surfaces, not forms. That is to say, a cone or a cylinder is not a "curved" form, nor a "flat" form - they are forms that are made up of both curving surfaces and flat surfaces, so we need to think of our intersections as being interactions between pairs of different surfaces. An intersection line may jump from one surface to another, meaning we go from focusing on one pair of surfaces to another pair, and this will influence the intersection line itself. For example, how when going from one surface of a box to another, we end up with a sharp corner in the intersection line to denote how we dramatically changed trajectories. This diagram further illustrates this point, while also demonstrating what happens when we replace a hard edge with a more rounded, gradual transition, which can help us to think about how the intersection line itself is simply following those surfaces. When they change, the resulting intersection changes.

Continuing onto your object constructions, I wanted to quickly note that there is an explicit instruction in the material that you appear to have missed, or ignored. In this section where it states students can (and are encouraged to) use ballpoint pen instead of fineliner, it does mention that you should not be switching pens during the process, and should stick to the same kind of pen throughout. You unfortunately chose to go in with a fineliner, using it as a "clean-up" pass. One of the major reasons we don't want students doing this is that it encourages them to go back over the entirety of their drawing, which shifts the focus from what they're doing in 3D space to simply tracing over flat lines on a flat page.

When it comes to your use of orthographic plans, I am by and large pleased with it. You've been fairly fastidious, and while I will point out shortly that there were some landmarks that were not defined with subdivisions (and therefore would have had to be estimated by eye when actually adding them in your 3D construction), you did adhere to the concept of precision throughout the majority of your approach. 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, as you've largely done, 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.

So the cases where you stopped short of pinning down certain landmarks include the button and the shape immediately surrounding it on this toothbrush. I've marked it out on the orthographic plan here - as you can see, we don't have any concrete information as to how we might situate these lines along each dimension of the structure, so when you went to draw it in your 3D construction, you would have had to guess or estimate - meaning, a decrease in precision.

There will inevitably be situations where you will catch yourself having forgotten to include something in the orthographic plan. In such cases, there's absolutely no harm in going back and updating the orthographic plan, like a living representation of the decisions you're making for the 3D construction. You also get to decide what it is you wish to include in your construction - you're not bound to capturing every little detail. Your references are ultimately just a source of information, so if there are things that are simply unreasonably complex that aren't entirely necessary for the purpose for which you're constructing the object, then you can always choose to leave them out.

Lastly, I can see that you've made various attempts to decorate or shade your drawings - so for example, adding hatching lines or filling areas in. As noted here in Lesson 2, we don't actually want to add shading to our constructions for this course (although some of the older demos do include it - we're gradually overhauling everything to keep the demo material in line with the current principles we want students to hold to). In general, keep in mind that these are just exercises. They're not about drawing a pretty picture or having something to show off at the end - so you shouldn't take them beyond what the instructions ask. Additionally, when it comes to filled areas of solid black, it's best to save those for cast shadows - that is, where one form blocks the light from reaching a different surface. The reason this is okay (and encouraged) is because it lines up with the core focus of the course, which is to develop students' understanding of 3D space. As a cast shadow is a shape we design to convey the relationship between the form casting the shadow and the surface receiving it, it falls comfortably within the kind of choices that will further the core focus of the course, rather than undermine or distract from it.

With that, I'll go ahead and mark this lesson as complete. Do be sure to pay closer attention to the instructions going forward, as the point about ballpoint/fineliner/clean-up passes etc. is also present in Lesson 7, which is very similar to what we've done here, just a lot more complex.