Answer: Yes they are equivalent square side lengths
Step-by-step explanation:
Diagram A has a circle with diameter 10 ft, so this is the side length of the square.
For diagram B, count along the bottom row and you'll count out 5 circles each of which have a diameter of 2 feet (double the radius of 1 ft), leading to a total square side length of 2*5 = 10 ft.
Both squares have a side length of 10 feet.