The geometry of the ammonia molecule NH3 is trigonal pyramidal. In this geometry, the nitrogen atom is at the center, and the three hydrogen atoms surround it, forming a pyramid-like shape. There is also a lone pair of electrons on the nitrogen atom, which contributes to the overall geometry.As for polarity, ammonia is a polar molecule. This is because nitrogen is more electronegative than hydrogen, which creates a difference in electronegativity between the N-H bonds. This results in a net dipole moment, making the molecule polar. The lone pair of electrons on the nitrogen atom also contributes to the polarity of the molecule.