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 8 (i).
- Complete the table for Figure 8 (ii).
- Which figure number will have a perimeter of 552 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 8
= (8 x 11 + 1) x 4
= 89 x 4
= 356 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 8
= (8 x 4 + 2) x 4
= 34 x 4
= 136 cm
(c)
(Figure number x 4 + 2) x 4 = 552
Figure number x 4 + 2 = 552 ÷ 4
Figure number x 4 + 2 = 138
Figure number x 4 = 138 - 2
Figure number x 4 = 136
Figure number = 136 ÷ 4
Figure number = 34
Answer(s): (a) 356; (b) 136; (c) 34