The length is about 28 more than three times the width. Denoted as (a) width, and as (b) the length. Then move on to lay the system of equations, as done below:
[tex]\begin{cases}2a+2b=136\\b=3a+28\end{cases}[/tex]
[tex]\begin{cases}2a+2b=136|:2\\b=3a+28\end{cases}[/tex]
[tex]\begin{cases}a+b=68\\b=3a+28\end{cases}[/tex]
[tex]\begin{cases}a+3a+28=68\\b=3a+28\end{cases}[/tex]
[tex]\begin{cases}4a=40|:4\\b=3a+28\end{cases}[/tex]
[tex]\begin{cases}a=10\\b=3*10+28\end{cases}[/tex]
[tex]\begin{cases}a=10\\b=58\end{cases}[/tex]
The short side has a length of 10 cm, and 58 cm long.
