Study the pattern.
- Complete the table.
- How many dots are there on each side of the triangle if the total number of dots on the triangle is 87?
(a)
Pattern for the number of dots on each side of the triangle
Pattern 1: 1 + 1 = 2
Pattern 2: 2 + 1 = 3
Pattern 3: 3 + 1 = 4
Formula:
Number of dots on each side of the triangle = Pattern number + 1
Pattern for the number of dots
Pattern 1: 1 x 3 = 3
Pattern 2: 2 x 3 = 6
Pattern 3: 3 x 3 = 9
Formula:
Total number of dots = Pattern number x 3
Number of dots for Pattern 5
= 5 x 3
= 15
Number of dots on each side of triangle for Pattern 21
= 21 + 1
= 22
Total number of dots for Pattern 21
= 21 x 3
= 63
(b)
Pattern number
= 87 ÷ 3
= 29
Number of dots on each side of the triangle
= 29 + 1
= 30
Answer(s): (a) 15, 22, 63; (b) 30