Given diameter of circle is d
∴ Diagonal of inner square = Diameter of circle = d
Let side of inner square EFGH be x
EG2=EF2+FG2 [ by Pythagoras theorem]
⇒d2=x2+x2
⇒d2=2x2⇒x2=d22
∴ Area of inner square EFGH =(side)2=x2=d22
But side of the outer square ABCD = Diameter of circle = d
∴ Area of outer square =d2
Hence, area of outer squares is not equal to four times the area of the inner square.