A rhombus is a parallelogram
A=base*height
is the formula for finding the area of a parallelogram
A=64*16
A=1024 square meters
Now
A=side²
is the formula for the area of a square
1024=s²
√1024=s
32=s
the square with the same area has each side length 32 m.
Hope it helps
All the best