CH3NH2, also known as methylamine, has a shape that can be described as trigonal pyramidal. This structure is due to the presence of a nitrogen atom that is bonded to three hydrogen atoms and one methyl group (CH3).
The nitrogen atom has one lone pair of electrons, which also influences the geometry of the molecule. According to the VSEPR (Valence Shell Electron Pair Repulsion) theory, the lone pair occupies more space than the bonding pairs, which pushes the hydrogen atoms closer together and results in the trigonal pyramidal shape. The bond angles in CH3NH2 are approximately around 107 degrees, slightly less than the ideal tetrahedral angle of 109.5 degrees due to the repulsion from the lone pair.