Geometry with Toothpicks and Marshmallows - Children make various lines, angles, and polygons using toothpicks as lines/sides and marshmallows as endpoints/vertices. Glue them on construction paper and use pieces of note cards to label and define each. I also had my kids write sentences explaining where they see these figures in the world around them.
Remnant in Time, a tunnel book by Mary Beth Boone. Tunnel books are difficult to photograph, but I tried to pick a shot of this that shows the concertina form of this book, as well as the multiple cut-outs that create the diorama-like scene that defines tunnel books.
Line- the different lengths and widths placed by each other composes an image of a woman's figure. By placing lines at various distances from one another, the image gets more structure and gives the illusion of a body. A variation in width gives more dimension to the image and illustrates a sense of realism.