The Greedy Triangle
In this book, a triangle explores all the different things he can make as a triangle—a sailboat, a roof, a piece of pie. But he decides he is bored with being a triangle and goes to the shape shifter to get another side and become a quadrilateral! He explores all the things he can be as a square—a computer screen, a picture frame, a game square. Again, he gets bored and goes to the shape shifter to get another side. This continues until the shape is almost round and rolls away from all his friends. In the end, he decides he wants to go back to being himself, a triangle.