How does the 3D structure of SP3 bonds of Carbon, Oxygen and Nitrogen cause them to form polar molecules?

How does the three dimensional structure
of SP3 bonds of Carbon, Oxygen and Nitrogen
cause them to form polar or non-polar
molecules?

The answer must include a 3d
diagram of the molecules, and a discussion of the
effect of their electron configurations for bonds to
H; and how their filled or bonded orbitals
contributes to the polar nature of the molecule.

PLEASE HELP, THANKS!