Question 784049
park is rectangular-shaped and has a {{{3mil}}} perimeter:

{{{P=3mil}}}

 The length {{{L}}} is {{{4}}} times the width {{{W}}}:

{{{L=4W}}}

since {{{P=2(L+W)}}}, substitute given values

{{{3mil=2(4W+W)}}}.....solve for {{{W}}}

{{{3mil/2=4W+W}}}

{{{3mil/2=5W}}}

{{{3mil/(2*5)=W}}}

{{{3mil/10=W}}}

{{{W=0.3mil}}}

now find {{{L}}}

{{{L=4W}}}

{{{L=4*0.3mil}}}

{{{L=1.2mil}}}

so,
Width: {{{0.3mil}}}
Length:{{{1.2mil}}}


check: plug in {{{P=2(L+W)}}}

{{{P=2(1.2mil+0.3mil)}}}

{{{P=2(1.5mil)}}}

{{{P=3mil}}}