Answer:
21 cm by 21 cm
Explanation:
The formula for the area of a square is A = x^2, where x is the length of any one side of the square. Here,
441 cm² = x²
This actually has two roots: {√441, -√441), but since x must be positive here, to be a dimension of the square, we choose +√441, or +21.
The dimensions of the square are 21 cm by 21 cm.