  The precise determination of the physical and dynamical parameters of the HIP
109951 triple star system (WDS J22161-0705AB) which is formed by the A, Ba, and
Bb components are presented. The binary nature of component B was recently
confirmed by studying the radial velocities. The analysis of the system follows
Al-Wardat's complex method for analyzing CVBS which employs Kurucz (Atlas9)
line blanketed plane-parallel atmospheres simultaneously with an analytic
method for dynamical analysis (we used Docobo's method) to calculate the
parameters of this triple system. The result of our study yielded the following
parameters: $T^{A}_{\rm eff}=5836\pm 80$ K, $R^{A}=1.090\pm0.039R_\odot$,
$\log$g$^{A}=4.45\pm0.06$, $\mathcal{M}^{A}=1.05\pm0.16\mathcal{M}_\odot$;
$T^{Ba}_{\rm eff}=5115\pm 80$ K, $R^{Ba}=0.596\pm0.05R_\odot$, $\log$
g$^{Ba}=4.60\pm0.07$, $\mathcal{M}^{Ba}=0.83\pm0.16\mathcal{M}_\odot$,
$T^{Bb}_{\rm eff}=4500\pm 80$ K, $R^{Bb}=0.490\pm0.06R_\odot$, $\log$
g$^{Bb}=4.65\pm0.07$, and $\mathcal{M}^{Bb}=0.67\pm0.16\mathcal{M}_\odot$ based
on the revised \textit{Hipparcos} parallax. The orbital solution gave a total
mass as $\mathcal{M}=2.59\mathcal{M}_\odot$ based on Gaia parallax and
$\mathcal{M}=2.15\mathcal{M}_\odot$ based on the revised \textit{Hipparcos}
parallax. The synthetic spectral energy distributions (SED) and synthetic
stellar photometry of the entire system and individual components are given and
compared with the available observational ones. Finally, the positions of the
system components on the HR diagram and the evolutionary tracks are given and
their formation and the evolution of the system are discussed.
