We can find the area by splitting the given figure in 2 subfigures, that is,
The area of the triangle is
[tex]\begin{gathered} A_T=\frac{base\times heigth}{2} \\ A_T=\frac{35\times23}{2} \end{gathered}[/tex]which gives
[tex]A_T=\frac{805}{2}=402.5m^2[/tex]On the other hand, the area of the rectangle is
[tex]\begin{gathered} A_R=\text{base}\times heigth \\ A_R=35\times12 \\ A_R=420m^2 \end{gathered}[/tex]Therefore, the total area is
[tex]\begin{gathered} A=A_T+A_R \\ A=402.5+420 \\ A=822.5m^2 \end{gathered}[/tex]Therefore, the shaded area is equal to 822.5 square meters, which corresponds to option B
