Rules for determination of shape of hybrid orbitals.

There is a very easy rule as compared to other rules.

s=1/2 [valence electron of central metal atom under consideration *number of monovalent groups surrounding the central metal atom               

               --(minus) charge of cation(if present) + charge of anion(if present)]

NOW,1. if s=2, then it,s shape is LINEAR(sp hybridisation)

       2.if s=3,then it,s shape is triangular planer sp2 hybridisation

         3.if  s=4,then  it, s shape is tetrahedral (SP3) or square planer(dsp2) 

       4.IF S=5,then it ,s shape is trigonal bipyramidal and so on.........

Besides this,this will be the exact proposed structure as the theory but certainly their will be deviations in the structure as per the no. and avalability of Lone pair of electrons around the central atom.FOR  Example the structure of water molecule is bent due to lone pairs against proposed structure i.e linear.