Supplementary angles are the ones that when you add them, the result is 180°.
Let's call the angle we are looking for "x", since it is supplementary to the angle of 19°, they add up to 180°:
[tex]x+19=180[/tex]From this equation, we can solve to find the supplementary angle x.
We solve for x by subtracting 19 to both sides of the equation:
[tex]\begin{gathered} x+19-19=180-19 \\ x=161 \end{gathered}[/tex]Answer: 161°