Bond angle in H₂O is explained by            theory and bond angle in H₂S , H₂Se , H₂Te  is explained by                 

 

In H₂O molecule , Oxygen atom has four electron pairs around it 

According to VSEPR theory, shape must be tetrahedral

But due to lp-lp repulsions bond angle decreases to 104.5^o

And  water molecule is bent (or) angular

In H₂S , H₂Se , H₂Te , H₂Po  the bond angle is around 90-93^o

It is assumed that p-orbitals of central atom participate in bonding

P-orbitals are 90^o  to each other , the bond angle is around  90^o - 93^o

Thus VBT explains the shapes of  H₂S , H₂Se , H₂Te , H₂Po