you can use PowerSelection APIs to filter all edges with the same length (note this is what it records in the script editor when I select one edge in the tree, and then from the "selection" tab choose "select edges with same length", and insert selection in the script editor):
PowerSelection.Edges.ByLength(EdgeSelection.Create(GetRootPart().Bodies[0].Edges[2]),
PowerSelectOptions(True), #true if you want to search across all bodies, false if you want to search only in the bodies[0]
SearchCriteria.SizeComparison.Equal)
now you can get 2 selections for same length, you can pythonically loop in one group of edges, to find if there is another edge coincident with it:
for example:
GetRootPart().Bodies[0].Edges[3].Shape.Geometry.IsCoincident(GetRootPart().Bodies[1].Edges[0].Shape.Geometry)
-Aniket