Answer
Bond angle 3 is 109.5 degrees, and bond angle 4 is 120 degrees.
Work Step by Step
The central Carbon is bonded to four atoms and has no lone pairs, meaning that it has a tetrahedral electron geometry. Thus, the bond angle is approximately 109.5 degrees in bond 3. Meanwhile, in bond 4, the central Carbon has no lone pairs and is bonded to three atoms. Because it has a trigonal planar molecular geometry, the bond angle is approximately 120 degrees.
