JAMB - Chemistry (2017 - No. 22)

The ammonia (NH\(_3\)) molecule has a trigonal pyramidal shape, with the three hydrogen atoms and the nitrogen atom forming a pyramid, and a lone pair of electrons on the nitrogen atom. 

Trigonal pyramidal and trigonal planar are distinct molecular geometries; trigonal planar has three atoms bonded to a central atom in a flat, triangular arrangement, while trigonal pyramidal has three atoms and one lone pair around the central atom, resulting in a pyramid shape.