  The Yang-Baxter and pentagon equations are two well-known equations of
Mathematical Physic. If $S$ is a set, a map $s:S\times S\to S\times S$ is said
to be a set theoretical solution of the Yang-Baxter equation if $$ s_{23}\,
s_{13}\, s_{12} = s_{12}\, s_{13}\, s_{23}, $$ where $s_{12}=s\times id_S$,
$s_{23}=id_S\times s$, and $s_{13}=(id_S\times \tau)\,s_{12}\,(id_S\times
\tau)$ and $\tau$ is the flip map, i.e., the map on $S\times S$ given by
$\tau(x,y)=(y,x)$. Instead, $s$ is called a set-theoretical solution of the
pentagon equation if $$ s_{23}\, s_{13}\, s_{12}=s_{12}\, s_{23}. $$ The main
aim of this work is to display how solutions of the pentagon equation turn out
to be a useful tool to obtain new solutions of the Yang-Baxter equation.
Specifically, we present a new construction of solutions of the Yang-Baxter
equation involving two specific solutions of the pentagon equation. To this
end, we provide a method to obtain solutions of the pentagon equation on the
matched product of two semigroups, that is a semigroup including the classical
Zappa product.
