Ans: B
Since $G$ is the centroid of $\Delta ABC$, then $BL = LC$, $CM = MA$ and $BN = NA$. Hence, $AB= 10\text{ cm}$, $BC = 26\text{ cm}$ and $AC = 24\text{ cm}$. By applying the Heron’s formula to $\Delta ABC$, we have
Since $G$ is the centroid of $\Delta ABC$, then $BL = LC$, $CM = MA$ and $BN = NA$. Hence, $AB= 10\text{ cm}$, $BC = 26\text{ cm}$ and $AC = 24\text{ cm}$. By applying the Heron’s formula to $\Delta ABC$, we have
$\begin{array}{rcl}
s & = & \dfrac{10 + 26 + 24}{2} \\
& = & 30 \text{ cm}
\end{array}$
Therefore, the area of $\Delta ABC$
$\begin{array}{cl}
= & \sqrt{s(s – AB)(s-BC)(s-AC)} \\
= & \sqrt{30(30-10)(30-26)(30-24)} \\
= & 120\text{ cm}^2
\end{array}$
