Question 666691
if one side (let it be {{{a}}}) is {{{3ft}}} shorter than three times  the other side (let it be {{{b}}}), then

{{{a-3ft=3b}}}..........1

The perimeter and area of a rectangle:


the perimeter is {{{P=2a+2b}}}


and the area is {{{A=a*b}}}


{{{a-3ft=3b}}}..........1..solve for {{{a}}}


{{{a=3b+3ft}}}.....plug it in  {{{P=2a+2b}}}


 {{{P=2(3b+3ft)+2b}}}


{{{P=6b+6ft+2b}}}


{{{P=8b+6ft}}}.....{{{P}}} is expressed in terms of side {{{b}}}



{{{A=(3b+3ft)b}}}

{{{A=3b^2+b*3ft}}}

{{{A=3(b^2+b*ft)}}}...{{{A}}} is expressed in terms of side {{{b}}}