To determine the equation that describes the pattern shown in the figures, we need to observe how the pattern grows from one figure to the next.

Observations:

• Figure 1: 3 dots (arranged in a single row)
• Figure 2: 6 dots (arranged in two rows of 3 dots each)
• Figure 3: 10 dots (arranged in three rows of 4 dots each)

Pattern Analysis:

1. Each figure increases the number of rows and also increases the number of dots in each row by one as we move from Figure 1 to Figure 3.
2. The pattern is triangular, where each figure adds an additional row with an increasing number of dots.

Number of Dots:

The number of dots in each figure appears to follow a triangular number sequence. The nth triangular number is given by the formula:

$T_n = \frac{n(n+1)}{2}$

Where:

• $T_n$ is the total number of dots in the nth figure.
• $n$ is the figure number.

Applying the Formula:

• Figure 1: $T_1 = \frac{1(1+1)}{2} = \frac{2}{2} = 1$ row (but it shows 3 dots, suggesting the first figure might be a starting base, so a small modification might be needed for dots).
• Figure 2: $T_2 = \frac{2(2+1)}{2} = \frac{6}{2} = 3$ rows (3 rows of 2, adjustment needed)
• Figure 3: $T_3 = \frac{3(3+1)}{2} = \frac{12}{2} = 6$ rows (adjusted row pattern, adjustment for dots)

Given the observations and the growth in rows, you might need an adjustment. The equation based on the figure might start from 3, 6, 10, which resembles a triangular number with a small adjustment (row shift).

So, if the nth figure rows are calculated from: $T_n = n + T_{n-1}$

• To get exact dots:
  • Dots in nth figure (n rows): $\sum_{i=1}^{n}$ (row with i + n adjustment.)

Adjusted Equation for Dots:

$D_n = \text{ Triangular number based on n with dot adjustment.}$

Would you like more details, or have any questions? Here are 8 related questions:

1. How would you describe the difference between arithmetic and geometric sequences?
2. What is a triangular number, and where does it commonly appear in mathematics?
3. How can the pattern of dots be used to derive the nth term in other sequences?
4. Can you form a general equation for other dot arrangements, such as square or hexagonal patterns?
5. How do you derive a formula for a pattern when given a different sequence of numbers?
6. What role does the concept of mathematical induction play in sequence patterns?
7. How can patterns like this be used in real-world problem-solving?
8. What are some other examples of triangular numbers in geometry or combinatorics?

Tip: Identifying patterns in sequences often involves recognizing common number sequences like arithmetic, geometric, or triangular sequences. Always start by writing out the first few terms and looking for a recursive or explicit formula.