Item 1
Find the dimensions of the square.

Area = 441 cm²

21 cm by 21 cm

Step-by-step 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.