The angle formed by the intersection of tangent and secant outside the circle equals half the difference of the intercepted arcs.
[tex] \frac{(18x-6)-(5x+17)}{2}=60 \\ 18x-6-5x-17=60*2 \\ 13x-23=120 \\ 13x=120+23 \\ 13x=143\\ x=143/13 \\ x=11[/tex]
Arc KNL = 18x-6 + 5x+17
= 23x + 11
= 23*11 + 11
= 264° ← answer