Question 670108
you know that a perimeter of the rectangle is:{{{P=2L+2W}}} where  {{{L}}} is the length and {{{W}}} is the width

if a perimeter of {{{P=126in}}} 

and if the width {{{W= 4in}}},then the length will be

{{{126in=2L+2*4in}}}

{{{126in=2L+8in}}}

{{{126in-8in=2L}}}

{{{118in=2L}}}

{{{118in/2=L}}}

{{{59in=L}}}