Recall that the formula for determining the area of a parallelogram is
[tex]\begin{gathered} A_{\text{parallelogram}}=bh \\ \text{where} \\ b\text{ is the base} \\ h\text{ is the height} \end{gathered}[/tex]Given that the height is 0.4 yards, and the area is 8.2 square yards. Substitute the following values and we get
[tex]\begin{gathered} A=b\times h \\ 8.2\text{ yards}^2=b\times0.4\text{ yards} \\ \\ \text{Divide both sides by 0.4 yards} \\ \frac{8.2\text{ yards}^2}{0.4\text{ yards}}=\frac{b\times0.4\text{ yards}}{0.4\text{ yards}} \\ b=20.5\text{ yards} \end{gathered}[/tex]Therefore, the base of the parallelogram is equal to 20.5 yards.