Final answer:
Here is an example of how the rectangular array of squares can be constructed:
```
X X X
X X X
X X X
X X X
```
Step-by-step explanation:
To model 4 x 3 = 12 using a rectangular array of squares, we can create a grid with 4 rows and 3 columns. Each square in the grid represents a value of 1.
In this grid, each "X" represents a square. There are 4 rows and 3 columns, resulting in a total of 12 squares.
This rectangular array visually demonstrates the multiplication of 4 rows and 3 columns, which equals 12. Each row represents a value of 4, and each column represents a value of 3. By combining 4 rows and 3 columns, we get a total of 12 squares.