Question 860237
Side length, x.
Perimeter, 4x.
Area, x^2.
The description seems {{{highlight(x^2=4x+12)}}};
area of square base, {{{x^2}}}, 
number of square units, same as area, is {{{4x+12}}}.


Work with {{{x^2-4x-12=0}}}.
{{{(x+2)(x-6)=0}}}.
The solution part which makes sense is {{{highlight(x=6)}}}.