Lewis dot structure in the case of NH3 is a representation of the outer electrons surrounding the nitrogen atom.
The Lewis dot arrangement in the case of ammonia reveals that
the N atom shares 1 pair of electrons with each of the three H atoms, resulting in a complete of 3 joined pairs of electrons.
The NH3 molecule adopts a three-sided pyramid-like structure because of the arrangement of the valence electrons
according to its Electron pair Beverage cup structure.
In the Lewis dotpoint representation of ammonia, the nitrogen atom is enclosed by three spots, each representing a pair of connected electrons with a hydrogen atom.
