if you drew a picture, you would get a right triangle with 2 equal legnt legs
(see attachment)
so
the side legnth is the legnth of each leg
remember
a^2+b^2=c^2
in a square, the sides are same legnth
therfor
a=b
2a^2=c^2
if a=4√2
2a^2=2(4√2)^2=2(16*2)=2(32)=64
64=c^2
sqrt both sides
8=c
the diagnoal is 8ft
