Final answer:
To declare a 2D array, decide the data type it will store, then use two pairs of brackets to indicate the dimensions. If you want the array to represent a certain area, such as 100 square meters, the side length for a corresponding square would be 10 meters, resulting in an array like 'int[][] squareArray = new int[10][10];'.
Step-by-step explanation:
To declare a 2 dimensional array, you'll need to specify the type of data it will hold, and then declare the array with two sets of square brackets, with each pair indicating the size of each dimension. For instance, in Java, you would write something like int[][] myArray = new int[5][10];, which creates a 2D array with 5 rows and 10 columns. If you're considering using this array to represent an area, you must decide how large the array needs to be based on the context of your problem.
For instance, if you want to express the array size as an area in meters, and also want to determine the side length for a square with the same area, you must first define the total area. If the total area is 100 square meters, a square with equal width and length (because it's square) can be computed by taking the square root of the area, which would be 10 meters on each side. Therefore, if you were creating an array to model this square area, it could be declared as int[][] squareArray = new int[10][10];.