  The final-state phases in $\bar{B} \to D \pi, D^* \pi$, and $D \rho$ decays
appear to follow a pattern similar to those in $D \to \bar{K} \pi$, $\bar{K}^*
\pi$, and $\bar{K} \rho$ decays. Each set of processes is characterized by
three charge states but only two independent amplitudes, so the amplitudes form
triangles in the complex plane. For the first two sets the triangles appear to
have non-zero area, while for the $D \rho$ or $\bar{K} \rho$ decays the areas
of the triangles are consistent with zero. Following an earlier discussion of
this behavior for $D$ decays, a similar analysis is performed for B decays, and
the relative phases and magnitudes of contributing amplitudes are determined.
The significance of recent results on $\ob \to D^{(*)0} \bar{K}^{(*)0}$ is
noted. Open theoretical and experimental questions are indicated.
