The perimeter of a rectangle is given by the formula
[tex]\begin{gathered} P_{rec\tan gle}=\text{ 2(L+B)} \\ \text{where L is the length and B is the breadth} \end{gathered}[/tex]From the question, we were given the perimeter P=32inches and the length L=11inches
To calculate for the unknown length, which is the breadth, we substitute the value of P and L into the formula
[tex]\begin{gathered} P_{rec\tan gle}=2(L+B) \\ \text{Make B the subject of the fomula} \\ \frac{P}{2}=\frac{2(L+B)}{2} \\ \frac{P}{2}=L+B \\ B=\frac{P}{2}-L \end{gathered}[/tex][tex]\begin{gathered} B=(\frac{32}{2}-11)\text{inches} \\ B=(16-11)\text{inches} \\ B=\text{ 5inches} \end{gathered}[/tex]Hence, the unknown side is 5inches