Triangle is hosting auditions for all the best shapes to be in his play, Shapes in Space. Circle, Square, and Star each get a part. But Trapezoid just doesn't "fit in." Is he even a shape? The others think he sounds like a type of dinosaur. Determined to show off his usefulness, Trapezoid tries to act like the other shapes, to no avail. Eventually, though, Trapezoid celebrates his own distinct shape properties in order to become part of the performance.