In the past few years, there has been a strong trend towards developing par
ametric, computer-aided design systems based on geometric constraint solvin
g. An effective way to capture the design intent in these systems is to def
ine relationships between geometric and technological variables. In general
, geometric constraint solving including functional relationships requires
a general approach and appropriate techniques to achieve the expected funct
ional capabilities. This work reports on a hybrid method that combines two
geometric constraint solving techniques: constructive and equational. The h
ybrid solver has the capability of managing functional relationships betwee
n dimension variables and variables representing conditions external to the
geometric problem. The hybrid solver is described as a rewriting system an
d is shown to be correct.