Each of the figures is made up of 1-cm toothpicks.
The table shows the number of toothpicks used to make the figures and their perimeters.

1. Find the number of toothpicks in Figure 12.
2. What is the perimeter of Figure 71?
3. Which figure requires a total number of 1191 toothpicks?

(a)
Pattern for the number of toothpicks
Figure 1: 1 x 8 + 7 = 15
Figure 2: 2 x 8 + 7 = 23
Figure 3: 3 x 8 + 7 = 31

Formula:
Number of toothpicks = Pattern number x 8 + 7

Number of toothpicks in Figure 12
= 12 x 8 + 7
= 103

(b)
Pattern for the perimeter of the figure
Figure 1 = 1 x 2 + 7 = 9
Figure 2 = 2 x 2 + 7 = 11
Figure 3 = 3 x 2 + 7 = 13

Formula:
Perimeter of the figure = Pattern number x 2 + 7

Perimeter of figure 71
= 71 x 2 + 7
= 149

(c)
Figure number x 8 + 7 = 1191
Figure number x 8 = 1191 - 7 = 1184
Figure number = 1184 ÷ 8 = 148

Answer(s): (a) 103; (b) 149; (c) 148