  The segment distribution around the center of gravity is investigated for a
special comb polymer (triangular polymer) having the side chains of the same
generation number, $g$, as the main backbone. Common to all the other polymers,
the radial mass distribution is expressed as the sum of the distribution
functions for the end-to-end vectors, $\{\vec{r}_{Gh}\}$, from the center of
gravity to the monomers on the $h$th generation; the result being, for a large
$g$, \begin{equation}
\varphi_{\text{triang}}(s)=\frac{1}{N}\left\{\sum_{h=1}^{g}\left(\frac{d}{2\pi\left\langle
r_{Gh}^{2}\right\rangle}\right)^{\frac{d}{2}}\text{Exp}\left(-\frac{d}{2\left\langle
r_{Gh}^{2}\right\rangle}s^2\right)+\sum_{h=2}^{g}\sum_{j=1}^{g-h}\left(\frac{d}{2\pi\left\langle
r_{Gh_{j}}^{2}\right\rangle}\right)^{\frac{d}{2}}\text{Exp}\left(-\frac{d}{2\left\langle
r_{Gh_{j}}^{2}\right\rangle}s^2\right)\right\}\notag \end{equation} It is found
that the mean square of the radius of gyration varies as $\left\langle
s_{N}^{2}\right\rangle_{0}\doteq\frac{7}{15}\,g\,l^{2}$, as
$g\rightarrow\infty$. Since $g\propto \sqrt{N}$ for the triangular polymer,
this leads to $\left\langle s_{N}^{2}\right\rangle_{0}^{1/2}\propto N^{1/4}$,
giving the same exponent as observed for the randomly branched polymer. On the
basis of the present result, we put forth that all the known polymers obey the
equality: $\left\langle s_{N}^{2}\right\rangle_{0}=A\, g\,l^{2}$, where $A$ is
a polymer-species-dependent coefficient and also depends on the choice of the
root monomer. We discuss the extension of this empirical equation.
