Question 148741
3600= 2x^2 + 10x + 25 
then

2x^2+10x+25-3600=0
2x^2+10x-3575=0

{{{x = (-10 +- sqrt( 10^2-4*2*(-3575) ))/(2*2) }}}=
 {{{x = (-10 +- sqrt( 28700 ))/(2*2) }}}=
 {{{x = (-10 +- sqrt( 28700 ))/(4) }}}

then solutions are  {{{x = (-10 + sqrt( 28700 ))/(4) }}} and {{{x = (-10 - sqrt( 28700 ))/(4) }}}

positive solution is
{{{x = (-10 + sqrt( 28700 ))/(4) }}}=39.85 (aprox)

So legs are  39.85 and 44.85 aprox