Each of the figure is made up of 4-cm sticks. The table shows the total length of sticks used for each figure and the perimeter of each figure.
- Complete the table for Figure 9 (i).
- Complete the table for Figure 9 (ii).
- Which figure number will have a perimeter of 1592 cm?
(a)
Pattern of the total length of sticks
Figure 1: (1 x 11 + 1) x 4 = 48 cm
Figure 2: (2 x 11 + 1) x 4 = 92 cm
Figure 3: (3 x 11 + 1) x 4 = 136 cm
Formula:
Total length of sticks = (Figure number x 11 + 1) x 4
Total length of sticks for Figure 9
= (9 x 11 + 1) x 4
= 100 x 4
= 400 cm
(b)
Pattern of the perimeter
Figure 1: (1 x 4 + 2) x 4 = 24 cm
Figure 2: (2 x 4 + 2) x 4 = 40 cm
Figure 3: (3 x 4 + 2) x 4 = 56 cm
Formula:
Perimeter of Figure= (Figure number x 4 + 2) x 4
Perimeter of Figure 9
= (9 x 4 + 2) x 4
= 38 x 4
= 152 cm
(c)
(Figure number x 4 + 2) x 4 = 1592
Figure number x 4 + 2 = 1592 ÷ 4
Figure number x 4 + 2 = 398
Figure number x 4 = 398 - 2
Figure number x 4 = 396
Figure number = 396 ÷ 4
Figure number = 99
Answer(s): (a) 400; (b) 152; (c) 99