Question 11(i)
Look at the following matchstick pattern of squares. The squares are not separate. Two neighbouring squares have a common matchstick. Observe the patterns and find the rule that gives the number of matchsticks in terms of the number of squares. (Hint: If you remove the vertical stick at the end, you will get a pattern of Cs.)
The column of 'number of matchsticks - 1' forms the multiplication table of 3. i.e., 3, 6, 9, 12,...
Let the number of squares be x.
The number of matchsticks used in each pattern is 1 more than 3 times he number of squares in it.
∴The number of matchsticks used in each pattern = 3x+1.