Question 1065468
It is a square - that much is given in the description.


x, the side length of this square photograph


{{{x^2+x^2=5^2}}}

{{{2x^2=5^2}}}

{{{x^2=5^2/2}}}
{{{x=5/sqrt(2)}}}

{{{highlight(x=5sqrt(2)/2)}}}