Question 802572
What is "bar model"?


The exercise is a common rectangle problem.   Let L = length and let w = width.

Translating the description gives {{{L=4w}}}, and {{{2w+2L=12.5}}}.


Substitute for L, since you have a formula for it from the description.
{{{2w+2(4w)=12.5}}}, and solve for w first.


{{{2w+8w=12.5}}}
{{{10w=12.5}}}
{{{w=(1/10)12.5}}}
{{{highlight(w=1.25=1&1/4)}}}


{{{highlight(L=4(1.25)=5)}}}