Krashy and Rosy are building houses. They only need to add the roof. But where can they find it? Both Krasy and Rosy spot a sauare piece of paper and they both go after it, tugging hard. Wally suddenly has an idea! He sees a pair of scissors and cuts the square paper diagonally -- making two triangles! Each triangle will make a perfect roof! In this episode, preschoolers learn about the shape - triangle.