Answer :
[tex]\begin{gathered} \text{triangle area = }\frac{high\cdot\text{ base}}{2} \\ \\ \text{From triangle B} \\ \sin (63)=\frac{high}{840} \\ \text{high}=840\cdot\sin (63) \\ \text{high}=\text{ 748cm} \\ \\ \text{triangle area = }\frac{748\cdot350\text{ }}{2}=130,900\operatorname{cm}^2 \\ The\text{ area of the triangle is }130,900\operatorname{cm}^2 \\ \end{gathered}[/tex]
