Question:
Find the centroid of ∆ABC whose vertices are A(2, 2), B(−4, −4) and C(5, −8).
Solution:
The given points are A(2, 2), B(−4, −4) and C(5, −8).
Here, $\left(x_{1}=2, y_{1}=2\right), \quad\left(x_{2}=-4, y_{2}=-4\right)$ and $\left(x_{3}=5, y_{3}=-8\right)$
Let $G(x, y)$ be the centroid of $\Delta A B C$. Then,
$x=\frac{1}{3}\left(x_{1}+x_{2}+x_{3}\right)$
$=\frac{1}{3}(2-4+5)$
$=1$
$y=\frac{1}{3}\left(y_{1}+y_{2}+y_{3}\right)$
$=\frac{1}{3}(2-4-8)$
$=\frac{-10}{3}$
Hence, the centroid of $\Delta A B C$ is $G\left(1, \frac{-10}{3}\right)$.