In the mean time, here is the Exercise 3 done just putting the principles in the back of my mind and using them to inform what I am actually seeing without completely measuring them out and making them line up exactly to a vanishing point on the horizon, as I couldn't even do that with a printout of the actual view. This was drawn from actually looking at the bookcase and the yoga blocks, not from looking at the photograph I took of them. I'm sure had I drawn from the photo it would be more accurate, but I'm trying to learn to draw from seeing things in actual life. It's easy to draw from a photograph because the transition from 3D to 2D has already been made for you. I don't know why it's so hard to do it in actual life. Anyway, here is my attempt. I only have 3 yoga blocks, so it's not 4 boxes, but maybe the books can count.