In the figure, the L-shaped shaded piece is cut from a metal plate of uniform thickness. The point that corresponds to the center of mass of the L-shaped piece is

Let the mass of a small square = m
Hence the mass of the square plate = 48m
And the mass of the L shaped plate = 24m
Let the position of centre of mass of remaining structure be ${\overrightarrow{r}}^{\mathrm{\prime }}$

${\overrightarrow{r}}^{\mathrm{\prime }}=\frac{48m\times 0-24m\times \overrightarrow{r}}{48m-24m}=-\overrightarrow{r}$

The point opposite to O' is point 2.