Solution:
Note that:
Looking at the notes, we can conclude that ∠K measures 150° because of the equation (∠L = ∠K).
Hoped this helped!
Alternative angles have sum 180°
[tex]\\ \rm\hookrightarrow 150+x=180[/tex]
[tex]\\ \rm\hookrightarrow x=180-150[/tex]
[tex]\\ \rm\hookrightarrow x=30[/tex]