We introduce a new class of planar graphs called triangle graphs. Firs
t, we present a formal way of constructing and characterizing triangle
graphs, and then show that they characterize the adjacencies of arbit
rary triangulations and they are three-colorable for a certain subclas
s of triangulations. Subsequently, we discuss an application of triang
le graphs to the parallel finite element solution of elliptic partial
differential equations on triangulated domains.