Question 254586
A=s^2
50=s^2
let c=diagonal a and b the sides
a=s
b=s
a^2+b^2+c^2 where c=the diagonal and both  a^2 and b^2 =s^2 
The diagonal will be 2s^2=c^2
2*50=c^2
100=c^2
c=10 the diagonal equals 10