Solve the following math problem step by step. The last line of your response should be of the form Answer: \boxed{$Answer} where $Answer is the answer to the problem.

<image>In the figure, $ \overline{GK} \cong \overline{GH}$ and $ \overline{HK} \cong \overline{KJ}$. If $m \angle HGK=28$, find $m \angle HJK$.