a) Just add 1 square on the right and 1 square on top for figure 4. Add 1 more in each place for figure 5.
b) Each stage adds a square above and a square to the right. The pattern never decreases. This trend is shown by figures 1, 2, and 3.
c) Figure 0 would be a single square. Simply follow the pattern in reverse. As the figure number decreases, squares are removed from the right and the top rather than added.
