  We classify edge-to-edge tilings of the sphere by congruent almost
equilateral pentagons, in which four edges have the same length. Together with
our earlier classifications of edge-to-edge tilings of the sphere by congruent
equilateral pentagons of other types, and our classification of edge-to-edge
tilings of the sphere by congruent quadrilaterals or triangles, we complete the
classification of edge-to-edge tilings of the sphere by congruent polygons.
