When the central atom has 6 bonding pairs of electron the geometry is octahedral. All the bond angles are 90Ü.
In octahedral geometry 4 terminal atoms lie in a square plane with the remaining 2 terminal atoms perpendicular to the square plane.
When a bonding pair of electrons is replaced with a nonbonding pair geometry is square pyramidal.
When the central atom has 4 bonding pairs of electrons and 2 nonbonding pair the geometry is square planar.
