base= 4 inches
Explanation
the area of a parallelogram is given by:
[tex]\text{Area}_{shape}=base\cdot heigth[/tex]then
Let
base= unknown= b
height= 10 in
Area= 40 square inches
replace,
[tex]\begin{gathered} \text{Area}_{shape}=base\cdot heigth \\ 40in^2=b\cdot10in\cdot \\ \text{now, to solve for b, divide both sides by 10 in} \\ \frac{40in^2}{10\text{ in}}=\frac{b\cdot10\text{ in}}{10\text{ in}} \\ 4\text{ in=b} \end{gathered}[/tex]Hence , the base is 4 inches.
I hope this helps you