The molecular geometry of ammonia 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 structure. The nitrogen atom also has one lone pair of electrons, which contributes to the overall shape of the molecule.The bond angles between the nitrogen atom and each of the three hydrogen atoms in ammonia are approximately 107.5 degrees. This angle is slightly smaller than the ideal bond angle of 109.5 degrees in a regular tetrahedron due to the repulsion between the lone pair of electrons and the bonding pairs of electrons.