Let the side of the equilateral Δle 'a' and the side of the square be 'x' we know, area of equilateral Δ=√34a2
64√3=√34a2
∴a2=82×22
a=16 cm
Perimeter of equilateral Δ=3(16)
= 48 cm
Hence, perimeter of square = 48 cm
i.e., 4×=48⇒x=12 cm
Area of square =x2
=(12)2
=144