Adjacent Angles<span> are </span>two angles<span> that share a common vertex, a common side, and no common interior points. (They share a vertex and side, but </span>do<span> not overlap.) A </span>Linear Pair<span> is </span>two<span> adjacent</span>angles<span> whose non-common sides </span>form<span> opposite rays. ... ∠1 and ∠3 are not </span>vertical angles<span> (they are a </span>linear pair<span>).</span>
Add them up and you have your answer
The new mean age will be greater than 14.2 years because the teacher is older than the previous mean.