Each of the figure is made up of 3-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 5 (i).
- Complete the table for Figure 5 (ii).
- Which figure number will have a perimeter of 1062 cm?
(a)
Pattern of the total length of sticks
Figure 1: (1 x 11 + 1) x 3 = 36 cm
Figure 2: (2 x 11 + 1) x 3 = 69 cm
Figure 3: (3 x 11 + 1) x 3 = 102 cm
Formula:
Total length of sticks = (Figure number x 11 + 1) x 3
Total length of sticks for Figure 5
= (5 x 11 + 1) x 3
= 56 x 3
= 168 cm
(b)
Pattern of the perimeter
Figure 1: (1 x 4 + 2) x 3 = 18 cm
Figure 2: (2 x 4 + 2) x 3 = 30 cm
Figure 3: (3 x 4 + 2) x 3 = 42 cm
Formula:
Perimeter of Figure= (Figure number x 4 + 2) x 3
Perimeter of Figure 5
= (5 x 4 + 2) x 3
= 22 x 3
= 66 cm
(c)
(Figure number x 4 + 2) x 3 = 1062
Figure number x 4 + 2 = 1062 ÷ 3
Figure number x 4 + 2 = 354
Figure number x 4 = 354 - 2
Figure number x 4 = 352
Figure number = 352 ÷ 4
Figure number = 88
Answer(s): (a) 168; (b) 66; (c) 88