Starting with your cylinders around arbitrary minor axes, your work here is by and large looking pretty good, with a couple things to keep in mind:

• Keep an eye on whether or not you're consistently drawing through your freehanded ellipses two full times - it's clearly your intent to do so, but it's easy to fall a little short, and I am noticing cases where you're stopping at around 1.5 turns of the shape. Not a big deal, just something to be aware of if you didn't notice it yourself, so you can consciously push yourself to complete the two full turns.

• A similarly minor point, since I'm not noticing issues as a result, but generally we do encourage students to draw larger where they can (so for example in the box challenge it was 5-6 boxes per page), as this helps give the brain more room to engage its spatial reasoning skills. It just makes the exercises more impactful than having a lot of small forms crammed into a page.

Additionally, keep in mind that as our cylinders are foreshortened, it manifests in two main ways - the shift in scale from one ellipse to the other, and the shift in degree. Because these both work to signify the same thing, it does mean that they work in tandem - so as the scale shift increases, and those side edges of the cylinder pinch together to achieve a more dramatic convergence, so too would the far end get more notably wider, as its degree shift matches the shift in scale. So for example, if you look at 149, you'll see that while the degree doesn't change much from one end to the other, the scale shift/convergence of the side edges is more significant, causing it to look a little off. This is because the two different "shifts" aren't entirely agreeing with one another.

Continuing onto the cylinders in boxes, your work here is generally coming along quite well - except for one notable issue. 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.

The notable issue is that it doesn't seem you're extending your minor axis lines at all - or at least, not that I can see. Generally in the direction running down the cylinder, you tend to have 4 lines extended, and they match up with the boxes' 4 edges, without any visible extensions of the ellipses' individual minor axes. There are cases where you appear to perhaps be extending the black line you drew for the minor axis before drawing your ellipses (the one we use to help us align our ellipses correctly), but that is not the same as checking the true alignment of the ellipses themselves.

Skipping over one of the three line extensions applied to each ellipse is a lot like checking a dark room for monsters with a flashlight, but skipping one corner - they can always be hiding in the spot you skipped, so it's very important to ensure that you are applying the error checking strategy in its entirety.

Be sure to do so going forward, when practicing this exercise as part of your warmups. I'll go ahead and mark this challenge as complete.