Question 845394
Let x = the side length of the square of sheet metal.


The height will be 6, the length of the piece turned upward.
The length of the base will be x-2*6.


VOLUME:  {{{highlight_green((x-12)(x-12)6=864)}}}.
{{{6(x-12)^2=864}}}
{{{x^2-24x+144=864/6}}}
{{{x^2-24x+144=144}}}
{{{x^2-24x=0}}}
{{{x(x-24)=0}}}
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The acceptable answer is {{{highlight(x=24)}}}.
The uncut square sheet metal is 24 feet on each side.