another pinner said: We've been studying Frank Stella's Protractor Series. After learning about the artist and analyzing his work through a PowerPoint, students began drawing their own designs using a pencil, protractor, and ruler. Next day, students outlined their design with sharpie, and started coloring with colored pencil. I had several students tell me this was the most favorite project they've ever done... they are easy to please! Some of their design are very mathematical.