Starting with your cylinders around arbitrary minor axes, this exercise breaks down into a couple main things that I look out for:

• While you did indeed have a little bit of a struggle with the alignment of your ellipses to your minor axes, you definitely improved over the set and showed a good deal of patience and care in identifying the correct ones after the fact, and learning from them. There's still some work to be done in being able to nail that alignment more consistently, but the frequency of doing so correctly has definitely increased a fair bit.

• I noticed that between the two ellipses of a given cylinder, you generally haven't been really shifting the degree of one relative to the other. As explained here, the farther ellipse should always be proportionally wider than the closer end. How much wider depends on the foreshortening being applied to the form, so we can look at how much smaller in scale we're making the far end, and based on that, judge how much wider that far end should be in turn. Some of your cylinders (perhaps intentionally, but likely not) like 149 actually show this correctly. With that example, the far end is slightly wider, and slightly smaller, and so both of these aspects of foreshortening are consistent with one another. Looking however at 144, where the far end is significantly smaller, this means that it should also have been more significantly wider in order to remain consistent. Since you kept roughly the same degree for that far ellipse, the viewer can tell there's something off about the cylinder, though they may not be able to pinpoint exactly what that is.

Moving onto your cylinders in boxes, your work here is actually quite solid, and I'm glad to see that you caught that issue involving your minor axis on your own, and started to apply it more correctly in your later cylinders. The thing about this exercise is that it is actually more about the boxes themselves, and specifically learning how to draw them with two proportionally square, opposite faces (in order to make them suitable for containing a proper cylinder).

Similarly to how in the box challenge we used line extensions to analyze our results and to identify which direction in which our approach should be shifted to improve those results the next time around, here we continue the same trend but add three additional lines per ellipse: the minor axis, and the two lines created by the contact points. These additional lines will only line up with the vanishing point of the box itself if the ellipses represent circles in 3D space that sit along the surface of the given box. Therefore if those lines are a little off, then making adjustments to bring them more in line will in turn get the ellipses closer to being circles in 3D space. This then means that the plane enclosing it gets closer to being square.

Looking at your work, for the most part there was definitely a big push in your ability to judge, by eye and by instinct, the proportions required to make the faces of your boxes square in a variety of orientations and configurations. This skill that you've developed will serve you well throughout lesson 6.

All in all, your work is coming along well. I'll go ahead and mark this challenge as complete, but be sure to mind the relationship in the degree of the ellipses on either end of a cylinder.