El Nombre shows Juan what a rectangle is (with a plank of wood, the cart's side and the then-still-unnamed Pedro and Juanita's piece of cardboard), while Sammy Shape pays a visit to Old Mother Hubbard's cottage to find out "what makes a rectangle a rectangle" for "Shapewatch" (which, like the "Crime Spot" sketch from the previous series, is a spoof of "Crimewatch") and met by her dog (who, as in the nursery rhyme, wants a bone, but they find a rectangular biscuit instead), a rectangular man goes for a swim at a swimming pool (after walking up a staircase, taking an elevator and walking up another staircase), Humpty Dumpty is asked to identify the shape of one of the bricks in the wall he is sitting on (which he does just before he falls), and a woman named Jane keeps in touch with her grandmother by writing a rectangular letter, posting it into a postbox which has a rectangular slot and door, then arriving at her house after she receives it.