Lesson in the “Basic Unit” principle. Same exercise in terms of drawing with negative space, only except this time when you start you have to pick the Basic Unit or starting shape that essentially is your anchor for the picture. In essence, this is probably one of the most important exercises in the book. If you do not pick a good starting point then you can pretty much guarantee that something will be off in the final drawing.
My basic unit for me in this drawing of one of my kitchen chairs was the middle negative space in the back of the chair. I drew that first and then the remaining negative spaces. Afterwards I added the tone to the background.