Question 237439
With these box problems, what they do,
usually, is cut small squares out of the corners
and then fold up the 4 equal height sides to 
make the box.
So, I'll say that each of these 4 equal squares will have
dimensions {{{x*x = x^2}}} cm2
To get the area of the bottom after the sides are
folded up, I subtract {{{2x}}} from each side.
{{{(29 - 2x)*(33 - 2x) = 525}}}
{{{957 -66x -58x + 4x^2 = 525}}}
{{{957 - 124x + 4x^2 = 525}}}
{{{4x^2 - 124x + 432 = 0}}}
{{{x^2 - 31x + 108 = 0}}}
Use the quadratic formula
{{{x = (-b +- sqrt( b^2-4*a*c ))/(2*a) }}}
{{{a = 1}}}
{{{b = -31}}}
{{{c = 108}}}
{{{x = (-(-31) +- sqrt( (-31)^2-4*1*108 ))/(2*1) }}}
{{{x = ( 31 +- sqrt( 961 - 432 ))/2 }}}
{{{x = ( 31 +- sqrt( 529 ))/2 }}}
{{{x = ( 31 +- 23)/2 }}}
{{{x = (31 - 23)/2}}}
{{{x = 8/2}}}
{{{x = 4}}} 
and
{{{x = 31 + 23)/2}}}
{{{x = 54/2}}}
{{{x = 27}}} (can't be answer, too big)
The box has to be 4 cm deep
check answer:
{{{(29 - 2x)*(33 - 2x) = 525}}}
{{{(29 - 2*4)*(33 - 2*4) = 525}}}
{{{(29 - 8)*(33 - 8) = 525}}}
{{{21*25 = 525}}}
{{{525 = 525}}}
OK