Precalculus (6th Edition) Blitzer

The area of the triangle is approximately $\text{157 square meters}$.
Area of the triangle $=\frac{1}{2}ac\sin C.$ Putting the values in the formula, we get \begin{align} & \frac{1}{2}ac\sin C=\frac{1}{2}\left( 16 \right)\left( 20 \right)\left( \sin 102{}^\circ \right), \\ & \approx 157. \end{align} The area of the triangle is approximately $157$ square meters.