The area of a rectangle is given as
A = L x W
Given the area and the width, the missing side can be calculated as follows;
[tex]\begin{gathered} A=L\times W \\ 30=L\times6 \\ \text{Divide both sides by 6} \\ \frac{30}{6}=\frac{6L}{6} \\ 5=L \end{gathered}[/tex]The missing side therefore is 5cm
