CPM Homework Help : MC1 Problem 3-131

Study the pattern below. Sketch and label the fourth and fifth figures and then predict how many dots will be in the $100$ ^th figure.

$\Large\begin{array}{c c c} \bullet & \bullet & \bullet \end{array}\\ \; \; \text{Figure 1}$

$\Large\begin{array}{c c c} \bullet & \bullet & \bullet\\ \bullet & \bullet & \bullet \end{array}\\ \; \, \text{Figure 2}$

$\Large\begin{array}{c c c} \bullet & \bullet & \bullet\\ \bullet & \bullet & \bullet\\ \bullet & \bullet & \bullet \end{array}\\ \; \, \text{Figure 3}$

Hint:

This problem is very similar to problem 3-32. Go back and look at that one if you are having trouble getting started.

More Help:

In this pattern, you begin with $3$ dots and add $3$ more with each figure. Use this description to help you with this problem.