Question 1048872
So you know that the perimeter of the rectangle has to equal the amount of fencing,
{{{2W+2L=40}}}
{{{W+L=20}}}
and you know that the area of a rectangle is,
{{{A=W*L}}}
So set up a procedure to create a list of values, choose {{{W}}}, solve for {{{L}}}, calculate the area, {{{A}}}.
You know that {{{W}}} and {{{L}}} have to be non-zero and whole numbers so,
{{{W=1}}}
{{{1+L=20}}}
{{{L=19}}}
{{{A=1*19=19}}}
{{{W=1}}},{{{L=19}}},{{{A=19}}}
Now increment {{{W}}}.
{{{W=2}}}
{{{2+L=20}}}
{{{L=18}}}
{{{A=2*18=36}}}
{{{W=2}}},{{{L=18}}},{{{A=36}}}
Incremenet again,
{{{W=3}}}
{{{3+L=20}}}
{{{L=17}}}
{{{A=3*17=51}}}
{{{W=3}}},{{{L=17}}},{{{A=51}}}
Continue this way until you cannot (eventually {{{L=0}}} will signal it's time to stop).