Starting with the cylinders around arbitrary minor axes, your work here definitely started rather rough, but it improved over the set. This was less related to the core mechanics of the cylinders themselves, but more to do with the mark-making, as it tended to come off somewhat rushed and sloppy. As you progressed through this set however, it certainly improved. While I think it's much better by the end, I would still advise you to remember that the ghosting method must be used for every mark we freehand throughout this course. That means going through the planning phase to identify the nature of the mark you wish to make.

As to the other aspects of that exercise, you're doing a good job of checking your minor axis lines, and you're not shying away from catching even small discrepancies, which will help you continue to improve and avoid plateauing.

Continuing onto your cylinders in boxes, I can see that you've done a good job of following and applying the instructions for this one. 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 those line extensions as fastidiously and stringently as you have here, you've given yourself plenty of opportunity to analyze and derive useful information from each page, which was then applied to the next page's approach to further hone your sense of those proportions in space. This yielded solid progress through much of the set, up until 235 or so - after that you seemed to intentionally push the proportions of your boxes way outside of what would reasonably contain a cylinder with circular ends. The problem with this is that when it gets that far, it can result in the minor axis of our ellipses aligning to a different vanishing point, without us realizing it. For example, if we look at number 238 on this page, the minor axis lines end up coinciding with the red contact point lines, and you end up not identifying the minor axis line at all.

Ensuring that you always identify the minor axis line with the colour that matches its correct dimension (so in this case, the green lines that run down the length of the cylinder), and that you always ensure you're identifying each minor axis line and not skipping any, these issues will become more obvious and allow you to catch the problem. You might not realize immediately that the proportions are way off, but if you find a green line clustering with the reds, it's likely to make you pause and realize that something is wrong. That is the first step to identifying and correcting the problem.

The boxes after that point jump around between these extreme proportions and more regular ones, and on this page there are examples where you haven't applied your line extensions completely or at all, but these make up a small portion of the overall set. Just be sure to take more care to follow those instructions to the letter when practicing this exercise in the future, and as noted in regards to the cylinders around arbitrary minor axes, use the ghosting method for every freehanded line, ellipse, etc. throughout this course.

I'll go ahead and mark this challenge as complete.