The given formula is
[tex]A=\frac{1}{2}a\cdot b\cdot\sin C[/tex]Then, we replace all the given magnitudes
[tex]1718.58m^2=\frac{1}{2}\cdot67m\cdot113m\cdot\sin C[/tex]Now, we solve for angle C.
[tex]\begin{gathered} 2\cdot1718.58m^2=7571m^2\cdot\sin C \\ \frac{3437.16m^2}{7571m^2}=\sin C \\ C=\sin ^{-1}(\frac{3437.16}{7571}) \\ C\approx27 \end{gathered}[/tex]