Starting with your form intersections, for the most part you're progressing well. At this stage, we basically expect that students are fairly comfortable with intersections involving flat-surfaced objects, but still run into some issues when dealing with those forms with curved surfaces. That's more or less what we see here. As I've called out here on your first page, there were some spots where you got confused with the intersections involving your spheres.

As shown here, a lot of it comes down to understanding how each individual form's surfaces sit in and are oriented in space, and then identifying the pairs of surfaces that are intersecting at any given point along our intersection line. Of the arrows I drew, the curving ones define the relevant curve of the sphere, whereas the straight lines define the orientation of the corresponding surface of the box. Where we transition from one set of surfaces to another (which here was occurring at the edges of the box - that's essentially what the edge is, a transition from one surface to another), we hit a sharp corner from which we change the trajectory of our intersection. You were doing this correctly in other cases, but it definitely did get less certain when dealing with those curving surfaces. Again - this is pretty normal, and this exercise will come up once more in Lesson 7.

There are three other things I'd recommend:

• Fewer forms, but draw them bigger - this will help reduce the visual complexity of the problem (which you mentioned was especially challenging in the context of the object constructions, so I imagine it's impacting you here as well). Giving each form more space on the page also helps engage your brain's spatial reasoning skills more fully.

• Only draw the side of the intersection that is visible. I know we draw through our forms as it helps us better grasp the way in which these forms relate to one another in 3D space (so that's a case where it's more difficult, but that yields a beneficial result that is worth the additional cognitive resources that are required), but when it comes to the intersections themselves, the trade-off is not as favourable. Focusing only on what's visible will help keep your mind on the task at hand. The one exception to this are cases where the intersection as a whole is an ellipse - there, drawing the full ellipse will help you maintain the correct curvature.

• I noticed that when you were drawing your elliptical intersections, you did not draw through them two full times, as is required for all the ellipses we freehand throughout this course.

Continuing onto your object constructions, these are extremely well done. I get that dealing with all of those subdivisions is extremely taxing, and it takes vastly more time to keep track of all of the different lines (that's all it is - time, and it's a difficulty we've steadily ramped up throughout the course ever since the plotted perspective exercise, which similarly receives complaints of it being hard to keep track of what's what), but you are entirely capable of it, and what you've learned thus far has armed you with the ability to tackle that difficulty. Not happily, not easily, but this course has never been about doing things that are easy. It's been about doing difficult things because of the benefits they impart, and how they reinforce the lessons being taught.

That said, I unfortunately do have to contradict the advice you received, for the simple reason that drawing your subdivisions with different colours would break the point mentioned here about not going back over your linework with a different pen for a "clean-up pass". I want students to constantly be focusing on how the marks they're drawing represent things in 3D space, and when we rely on clean-up passes, it shifts the focus to simply tracing the lines in three dimensions, which can cause its own issues in how you're processing what you're learning.

When it comes time to make your object stand out from the construction, leveraging line weight as explained here aligns better with what we're doing in the course. That is, using it in localized areas to clarify how different forms overlap one another.

Anyway, I'll go ahead and mark this lesson as complete.