Final answer:
To declare an array with a size, you specify the number of elements during array creation. For instance, 'int[] myArray = new int[10];' in Java declares an array for 10 integers. Handling area and side length in relation to arrays involves calculating square dimensions based on area size.
Step-by-step explanation:
To declare an array with a size, you will specify the number of elements that the array will hold. In many programming languages, this is done at the time of array creation. For instance, in Java, you would declare an array of integers with a size of 10 like this:
int[] myArray = new int[10];
In this example, myArray is an array that can hold 10 integers. However, it seems there is a misunderstanding in the question as it refers to an area and the side length of a square. If we are discussing arrays in the context of dimensional space, for example in a two-dimensional array that represents a grid, the size of the array would correspond to the dimensions of the grid.
If the area is given, and you need to represent this in a square array where the length of each side is the same, you would calculate the side length as the square root of the area. For example, if an area is 100 square meters, the side length of a square with the same area would be:
side length = √area = √100 = 10 meters
Thus, you could declare a two-dimensional array to represent this square with dimensions 10x10.