  We discuss the geometry of the highly quantal nuclear three-body systems
composed of a core plus two loosely bound particles. These Borromean nuclei
have no single bound two-body subsystem. Correlation plays a prominent role.
  From consideration of the $B(E1)$ value extracted from electromagnetic
dissociation, in conjunction with HBT-type analysis of the two valence-halo
particles correlation, we show that an estimate of the over-all geometry can be
deduced. In particular we find that the opening angle between the two neutrons
in $^{6}$He and $^{11}$Li are, respectively, $\theta_{nn} =
{83^{\circ}}^{+20}_{-10}$ and ${66^{\circ}}^{+22}_{-18}$. These angles are
reduced by about 12% to $\theta_{nn} = {78^{\circ}}^{+13}_{-18}$ and
${58^{\circ}}^{+10}_{-14}$ if the laser spectroscopy values of the rms charge
radii are used to obtain the rms distance between the cores and the center of
mass of the two neutrons. The opening angle in the case of $^{11}$Li is more
than 20% larger than recently reported by Nakamura \cite{Nak06}. The analysis
is extended to $^{14}$Be and the two-proton Borromean nucleus $^{17}% $Ne where
complete data is still not available. Using available experimental data and
recent theoretical calculations we find, $\theta_{nn} = {64^{0}}^{+9}_{-10}$
and $\theta_{pp} = 110^{0}$, respectively.
