  The classical theory of plane projective geometry is examined constructively,
using both synthetic and analytic methods. The topics include Desargues's
Theorem, harmonic conjugates, projectivities, involutions, conics, Pascal's
Theorem, poles and polars. The axioms used for the synthetic treatment are
constructive versions of the traditional axioms. The analytic construction is
used to verify the consistency of the axioms; it is based on the usual model in
three-dimensional Euclidean space, using only constructive properties of the
real numbers. The methods of strict constructivism, following principles put
forward by Errett Bishop, reveal the hidden constructive content of a portion
of classical geometry. A number of open problems remain for future studies.
