Each of the figures is made up of 1-cm ice-cream sticks.
The table shows the number of ice-cream sticks used to make the figures and their perimeters.
- Find the number of ice-cream sticks in Figure 16.
- What is the perimeter of Figure 129?
- Which figure requires a total number of 3167 ice-cream sticks?
(a)
Pattern for the number of ice-cream sticks
Figure 1: 1 x 8 + 7 = 15
Figure 2: 2 x 8 + 7 = 23
Figure 3: 3 x 8 + 7 = 31
Formula:
Number of ice-cream sticks = Pattern number x 8 + 7
Number of ice-cream sticks in Figure 16
= 16 x 8 + 7
= 135
(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 129
= 129 x 2 + 7
= 265
(c)
Figure number x 8 + 7 = 3167
Figure number x 8 = 3167 - 7 = 3160
Figure number = 3160 ÷ 8 = 395
Answer(s): (a) 135; (b) 265; (c) 395