The percent s character describes the hybridization of an orbital. For example, an ,sp3 orbital has 25%s

Question:

The percent s character describes the hybridization of an orbital. For example, an ,sp3 orbital has 25%s character. Given the bond angles in each case, calculate the percent s character of (1) the orbital containing a lone pair and (2) the orbital used to form the bond to hydrogen in each of the following compounds. State any assumptions.
(a) NH3, H-N-H bond angle 107.3°
(b) H2O, H - O - H bond angle 105.5°