Describe the shapes of `BF_(3)` and `BH_(4)^(-)`. Assign the hybridisation of boron atom in these species.

Explanation

`BF_(3)[H]:(1)/(2)[3+3-0+0]=(6)/(2)=sp^(2)` (trigonal planar)
`BH_(4)^(-)[H]:(1)/(2)(3+4-0+1]=(8)/(2)=sp^(3)` (tetrahedral)