The classification of surfaces (orientable and nonorientable), Euler characteristic, connected sums, and polygon decompositions; manifolds, local homology, and knot complements.
The statements and examples are on Surfaces and manifolds (detailed).
The classification of surfaces (orientable and nonorientable), Euler characteristic, connected sums, and polygon decompositions; manifolds, local homology, and knot complements.
The statements and examples are on Surfaces and manifolds (detailed).