Answer
a) (left to right) $180^{\circ}$ & $180^{\circ}$
b) (left to right) $120^{\circ}$ & $120^{\circ}$
c) (left to right) $109.5^{\circ}$ & $109.5^{\circ}$
Work Step by Step
To easily predict the bond angles, one must first draw the lewis structure of each compound. Afterwards, count the number of groups around the atom in between the two bonds.
Any atom surrounded by two groups is linear ($180^{\circ}$). However, if the atom is surrounded by three groups, then it is trigonal planar ($120^{\circ}$). Lastly, if the atom is surrounded by four groups, then it may either be a tetrahedral or a trigonal pyramidal. A tetrahedral has four identical substituents while a trigonal pyramidal has one or more electron pairs.
