  For any northeast path $\nu$, we define two bivariate polynomials associated
with the $\nu$-associahedron: the $F$- and the $H$-triangle. We prove
combinatorially that we can obtain one from the other by an invertible
transformation of variables. These polynomials generalize the classical $F$-
and $H$-triangles of F.~Chapoton in type $A$. Our proof is completely new and
has the advantage of providing a combinatorial explanation of the relation
between the $F$- and $H$-triangle.
