Center Of Mass

\(\left(-\frac{\mathrm{a}}{2},-\frac{\mathrm{b}}{2}\right)\)

\(\left(\frac{\mathrm{a}}{8}, \frac{\mathrm{b}}{8}\right)\)

\(\left(-\frac{\mathrm{b}}{6},-\frac{\mathrm{a}}{6}\right)\)

\(\left(-\frac{a}{6},-\frac{b}{6}\right)\)