Starting with your cylinders around arbitrary minor axes, it appears to me that you may have attempted to simplify the nature of the exercise by drawing many of your cylinders with side edges that remain parallel on the page (or as close to it as you could manage - at times that means diverging a bit, sometimes converging a bit - but the intent does appear to be to keep them parallel). Unfortunately in doing so you've ended up running afoul of what was requested (as shown here the assignment section specifically requested that you include lots of variation for the rate of foreshortening).

Moreover, you've actually ended up breaking the rules of perspective as well. The cylinders we're drawing for this challenge are all freely rotated, not pinned down to any specific orientation in space. There is however only one orientation that would allow your side edges to run parallel on the page, towards a vanishing point at infinity (as discussed back in Lesson 1). It would only occur if the cylinder in question is oriented perpendicularly to the viewer's angle of sight, not slanting towards or away from them through the depth of the scene.

That of course would not allow those cylinders to be freely rotated in space, which is where we run into our issue.

In addition to this, there are a couple other points I wanted to quickly call out:

• You do not appear to be using the ghosting method when drawing your side edges, resulting in lines that are at times hesitant and wobbly, as well as lines that are redrawn multiple times, instead of committing to a single stroke. The ghosting method still needs to be employed for every structural mark we execute freehand throughout this course.

• There are a few cases where you do actually end up with convergence to your side edges - 71 for instance. This brings to light the reason I asked for lots of variety in the foreshortening. The foreshortening applied to a given form manifests in two distinct, but related ways. There's the far end getting smaller in overall scale, due to the convergence of the side edges towards a shared vanishing point, and then there's the fact that as explained here the far end gets wider than the end closer to the viewer. Both of these signify the same thing however - they tell us just how much of the length of the form is visible right there on the page, and how much of it exists in the "unseen" dimension of depth. Since both the shift in the degree from one end to the other and the shift in scale represent the same thing, they have to operate in tandem. As the far end gets smaller, it also needs to get wider in equal measure. So, for 71, instead of having that far end be at roughly the same degree as the closer end, it should be wider (since it's also that much smaller).

Fortunately the more difficult part of the challenge - the boxes in cylinders - are largely well done. This exercise is really all about helping develop students' understanding of how to construct boxes which feature two opposite faces which are proportionally square, regardless of how the form is oriented in space. We do this not by memorizing every possible configuration, but rather by continuing to develop your subconscious understanding of space through repetition, and through analysis (by way of the line extensions).

Where the box challenge's line extensions helped to develop a stronger sense of how to achieve more consistent convergences in our lines, here we add three more lines for each ellipse: the minor axis, and the two contact point lines. In checking how far off these are from converging towards the box's own vanishing points, we can see how far off we were from having the ellipse represent a circle in 3D space, and in turn how far off we were from having the plane that encloses it from representing a square.

In applying the line extensions correctly, you've allowed yourself to identify where your estimations were off, so you could make adjustments to your approach for the next page. One such issue that you've definitely improved upon is the tendency to have your lines converge in pairs, especially with the longer boxes/cylinders. The lines on one end would converge towards one vanishing point, and then the lines on the other end would converge towards their own vanishing point - despite being part of the same set, and thus needing to converge all together. Towards the end of the challenge, I did see notable improvement on this front.

So! While this latter part was done well, unfortunately you hit some major issues with the first part of the challenge, so that will need to be redone.