Answer
$\overline{x}=0$ and $\overline{y}=\dfrac{3}{3}=1$
Work Step by Step
We have a triangle has vertices $(-1,0), (1,0), (0,3)$, which is symmetric about the $y-axis$ and the center of mass has $x$-co-ordinate of $0$.
Also, the y-coordinate is a third of the distance of $(0,3)$.
Therefore, the center of mass is:
$\overline{x}=0$ and $\overline{y}=\dfrac{3}{3}=1$
