(a)    Look at the following matchstick pattern of squares (Fig 11.6). 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.)(b)   Fig 11.7 gives a matchstick pattern of triangles. As in Exercise 11 (a) above, find the general rule that gives the number of matchsticks in terms of the number of triangles.

Explanation

To solve the problem step by step, we will analyze the patterns of matchsticks for squares and triangles.

### Part (a): Matchstick Pattern of Squares

1. **Identify the Pattern for Squares**:
- For 1 square, we have 4 matchsticks.
- For 2 squares, we have 7 matchsticks.
- For 3 squares, we have 10 matchsticks.
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