Question 877934
You are implying, "diagonal".


{{{68/4=sideLength}}}


Let d = length of diagonal.  Use Pythagorean Theorem ....
{{{d=sqrt((68/4)^2+(68/4)^2)}}}
{{{d=sqrt(17^2+17^2)}}}
{{{d=sqrt(2*17^2)}}}
{{{highlight(d=17*sqrt(2))}}}