Sylvain brought you this diagram to see if you can help him with

Four x

>>37650882
let's use x for the side of the red square

in that case, x^2 is the area of the red square

the length of the red square's diagonal, and the diameter of the inner circle, and therefore the length of the side of the middle square, is x*sqrt(2)

similarly, the diameter of the outer circle is (x*sqrt(2)*sqrt(2)), or 2x, and so the side length of the blue square is 2x as well

(2x)^2 = 4x^2; therefore it is 4 times larger, QED

>>37650989
>QED
why do loser nerds always do this

is this jew gonna pay me

>>37651418
>jew
you just answered your own question

>>37650989
I was thinking along the same lines but you can just rotate the middle square 45 degrees an it becomes obvious that it must be half the size of the blue and twice the size of the red.