All electron pair in ammonia are Oriented in  ----- Geometry

No. of electron pairs on Central atom =   12(V+M-C+A)V=group no. of central atom(valence electrons)M=No. of monovalent groups(H,X) attached to central atomC=cationic chargeA=Anionic chargeNH3 :               Group no. of 'N' (valence e-) = 5                                     M = 3Electron pairs=12(5+3-0+0)=4According to VSEPR theory four electron pairs must be oriented tetrahedrallyto minimise repulsionsNo. of atoms directly attached to Central atom = Bond pairs = 3EP=4BP=3lone pairs(LP)=4-3 = 1Thus the structure of NH3 molecule is    Trigonal pyramidal                                                                    Orientation of all electron pairs = TetrahedralShape of the molecule = Pyramidal (or) Trigonal pyramidal