Answer
The area of the triangle is approximately $297\text{ square feet}$.
Work Step by Step
The formula for the area of the triangle, Q, with two sides b and c and an angle A inscribed between those sides, is:
$Q=\frac{1}{2}bc\sin A$
Putting the values in the formula, we get
$\begin{align}
& \frac{1}{2}bc\sin A=\frac{1}{2}\left( 20 \right)\left( 40 \right)\left( \sin 48{}^\circ \right) \\
& =400\left( 0.743145 \right) \\
& =297.25793 \\
& \approx 297
\end{align}$
The area of the triangle is approximately $297\text{ square feet}$.
