I just need someone to do the work and the process, but I know the answer

Answer:
8 yd
Step-by-step explanation:
The area of the square is found by the equation: A = s², where s is the length of a side.
Since we know the area, we can plug that number in: 64 = s²
Square root: ±√64 = s
Simplify: s = 8 yd (no negatives because distances must be > 0)