Fixing Triangle, TriangleStrip and Vertex.

src/Cxx/GeometricObjects/Triangle.cxx

src/Cxx/GeometricObjects/TriangleStrip.cxx

src/Cxx/GeometricObjects/Vertex.cxx

src/Python.md

src/Python/GeometricObjects/Triangle.md

src/Python/GeometricObjects/Triangle.py

src/Python/GeometricObjects/TriangleStrip.md

src/Python/GeometricObjects/TriangleStrip.py

src/Python/GeometricObjects/Vertex.md

src/Python/GeometricObjects/Vertex.py