The teacher helps the students see that each successive square contains the previous square within it. Thus, the number of segments on a 3times3 square can be found by adding the number of segments found on a 2times2 square to the number of new segments that can be created using the "new" pegs within the 3times3 square. The teacher has the students verify—by direct measurement or by treating the diagonal lengths as hypotenuses of right triangles—that all segments are really of different lengths. The students then record the number of segments of different lengths in each square and note the pattern of growth, as shown in figure 6.35.