Precalculus (6th Edition) Blitzer

The area of the triangle is approximately $\text{16 square yards}$.
Area of the triangle $=\frac{1}{2}ac\sin B$ Putting the values in the formula, we get \begin{align} & \frac{1}{2}ac\sin B=\frac{1}{2}\left( 8 \right)\left( 5 \right)\left( \sin 125{}^\circ \right) \\ & \approx 16 \end{align} The area of the triangle is approximately $16$ square yards.