Question 1136790
u, uniform border width


{{{(2u+6)(2u+10)=117}}}
Note that if you can find two factors of 117 which differ by 4, you can find each dimension of the outside border and solve for u.  Otherwise, solve a quadratic equation maybe using general formula solution.



{{{117=9*13}}}
{{{and}}}
{{{13-9=4}}}.


{{{2u+6=9}}}
{{{2u=3}}}
{{{highlight(u=1&1/2)}}},{{{feet}}}