According to the given diagram, d and 46° are vertical angles, which means d = 46°.
Then, using the supplementary angles theorem, we have
[tex]\begin{gathered} d+82+b=180 \\ 46+b+82=180 \\ b=180-46-82 \\ b=52 \end{gathered}[/tex]On the other hand, a and 134 are vertical angles, so a = 134°.
Then, using the exterior angle theorem, we have
[tex]\begin{gathered} a=b+c \\ 134=52+c \\ c=134-52 \\ c=82 \end{gathered}[/tex]