The figure shows a pattern formed using some wooden rods.
- How many wooden rods are used to form 65 squares?
- How many squares can be formed using 316 wooden rods?
(a)
Pattern for the number of wooden rods
1 square: 1 x 3 + 1 = 4
2 squares: 2 x 3 + 1 = 7
3 squares: 3 x 3 + 1 = 10
Formula
Number of wooden rods = Number of squares x 3 + 1
Number of wooden rods for 65 squares
= 65 x 3 + 1
= 196
(b)
Number of squares x 3 + 1 = 316
Number of squares x 3 = 316 - 1
Number of squares = 315 ÷ 3
Number of squares = 105
Answer(s): (a) 196; (b) 105