${\text{CS}}_{\text{2}}\left(\text{:}\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{S}}}\text{=}\text{C}\text{=}\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{S}}}\text{:}\right)\text{=}$ orientation of two electron pairs around carbon in linear.
${\text{SO}}_{\text{2}}\left(\text{:}\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{O}}}\text{=}\stackrel{\mathrm{..}}{\text{S}}\text{=}\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{O}}}\text{:}\right)\text{=}$ orientation of three electron pairs is trigonal planar, but presence of one lone pair makes the structure bent.
${\text{BF}}_{\text{3}}\left(\text{:}\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{F}}}-\underset{\text{:F:}}{\underset{\text{|}}{\stackrel{}{\text{B}}}}-\underset{\mathrm{..}}{\stackrel{\mathrm{..}}{\text{F}}}\text{:}\right)-{\text{NH}}_{\text{3}}\left(\text{H}-\underset{\text{H}}{\underset{\text{|}}{\stackrel{\mathrm{..}}{\text{N}}}}-\text{H}\right)-$ orientation of three electron pairs is trigonal planar, Since all electron pairs are bond pairs. Therefore, structure is trigonal planar. $\mathrm{N}{\mathrm{H}}_3\left(\mathrm{H}-\underset{\mathrm{H}}{\underset{|}{\stackrel{.\mathrm{}.}{\mathrm{N}}}}-\mathrm{H}\right)-$ orientation of four electron pairs is tetrahedral, but presence of one lone pairs make structure trigonal pyramidal.