This work reports on the implementation of a two-dimensional, variational geometric constraint solver based on a constructive approach. The solver computes a solution in two phases. First, using rewrite rules, the solver builds a sequence of construction steps. Then, the construction steps are carried out to generate an instance of the geometric object for the current dimension values. We discuss some issues concerning the data representation and the rules used. Then a simple example illustrates how the solver works. Finally we give a correctness proof of the solver.