It is important to know that the shaded area refers to the difference between the large rectangle and the smaller. So, let's find the area of each rectangle.
[tex]\begin{gathered} A_{\text{large}}=bh=16ft\cdot12ft=192ft^2 \\ A_{\text{smaller}}=bh=12ft\cdot4ft=48ft^2 \end{gathered}[/tex]
Then, we subtract
[tex]A_{\text{shaded}}=192ft^2-48ft^2=144ft^2[/tex]
Therefore, the area of the shaded region is 144 square feet.
