The H $-$ O $-$ H bond angle in H2O is smaller than the H $-$ N $-$ H bond angle in NH3.
The H $-$ C $-$ H bond angle in CH4 is larger than the H $-$ N $-$ H bond angle in NH3.
The H $-$ C $-$ H bond angle in CH4, the H $-$ N $-$ H bond angle in NH3, and the H $-$ O $-$ H bond angle in H2O are all greater than 90o.
The H $-$ O $-$ H bond angle in H2O is larger than the H $-$ C $-$ H bond angle in CH4.