Answer: the area of square A is the 25% of the area of square B.
Explanation:
If the length of the side of square A is La, and the length of the side of square B is Lb.
We have that:
La = 0.5*Lb
(because the length of the side of square A is the 50%, or 0.5 in decimal form, of the length of the side of square B)
The area of square B is Ab = Lb*Lb = Lb^2
The area of square A is Aa = La*La = 0.5*Lb*0.5*Lb = 0.5^2*Lb^2
we can replace Lb^2 to the area of square B = Ab
Aa = 0.5^2*Lb^2 = (0.5^2)*Ab = 0.25*Ab
Then the area of square A is 0.25 times the area of square B, we can multiply the factor by 100% to obtain the percentage.
0.25*100% = 25%
the area of square A is 25% of the area of square B.