We have seen that the use of polygons in modelling linkages is quite convenient,
as the model in question can be used to determine whether a pair(or any
number of pairs) of linkages are equivalent, and whether one can be moved
into the other. The effectiveness of this method can be enhanced through
the use of a linear-time algorithm for reconfiguring linkages in the plane
through a "flexing" of its hinges, but the analog in three dimensions remains
both unbounded in its complexity and an area of study for Computational Geometers.