The base of the parallelogram is 18 inches and the height is 6 inches
Mathematically, the base and the height of a parallelogram multiplied by one another will give the area of the parallelogram
Let the height be h
The base is 3 times this, so we have 3 * h = 3h
The product of this two will give 108
Thus;
[tex]\begin{gathered} h\text{ }\times\text{ 3h = 108} \\ 3h^2\text{ = 108} \\ h^2\text{ = }\frac{108}{3} \\ h^2\text{ = 36} \\ h\text{ = }\sqrt[]{36} \\ h\text{ = }\pm6 \\ \text{ height cannot be negative; so h = 6 inches} \\ b\text{ = 3}\times\text{ h = 3}\times\text{ 6 = 18 inches} \end{gathered}[/tex]