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 4 (i).
- Complete the table for Figure 4 (ii).
- Which figure number will have a perimeter of 606 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 4
= (4 x 11 + 1) x 3
= 45 x 3
= 135 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 4
= (4 x 4 + 2) x 3
= 18 x 3
= 54 cm
(c)
(Figure number x 4 + 2) x 3 = 606
Figure number x 4 + 2 = 606 ÷ 3
Figure number x 4 + 2 = 202
Figure number x 4 = 202 - 2
Figure number x 4 = 200
Figure number = 200 ÷ 4
Figure number = 50
Answer(s): (a) 135; (b) 54; (c) 50