please help me with my assignment question

Answer:
s = 21 cm
Step-by-step explanation:
Square is s x s = area
So you just take the square root button of the calculator to find that 21 x 21 is 441.
Answer:
21
Step-by-step explanation:
Area of Square formula: side x side
s^2=441
square root both sides:
s=√441=21