c
 ધારો કે, \(m\) દળ ધરાવતા ત્રણ કણો આ ત્રિકોણનાં શિરોબિંદુઓ પર છે. (જુઓ આકૃતિ)

\(\begin{gathered}
  {m_1}\, = \,\,{m_2}\,\, = \,\,{m_3}\,\, = \,\,m \hfill \\
  \mathop {{r_1}}\limits^ \to  \, = \,\,(0,\,\,0)\,,\,\,\,\,\,\mathop {{r_2}}\limits^ \to  \, = \,\,(b,\,\,0),\,\,\,\,\,\,\mathop {{r_3}}\limits^ \to  \, = \,\,(0,\,\,\,h) \hfill \\ 
\end{gathered} \)

\({r_{cm}}\, = \,\,\frac{{{m_1}\,{r_1}\, + \,\,{m_2}\,{r_2}\, + \,\,{m_3}\,{r_3}}}{{{m_1}\, + \,\,{m_2}\, + \,\,{m_3}}}\,\,\,\,\,\)

\( = \,\,\frac{{m(0,\,\,0)\,\, + \,\,m(b,\,\,0)\,\, + \,\,m(0,\,\,h)}}{{m\, + \,\,m\, + \,\,m}} = \,\,\frac{{m(b,\,\,h)}}{{3\,\,m}}\,\,\,\, \)

\(= \,\,\left( {\frac{b}{3},\,\,\frac{h}{3}} \right)\)